Antifouling materials

ABSTRACT

The invention provided herein presents a novel family of antifouling agents based on hydroxylated and fluorinated compounds.

FIELD OF THE INVENTION

The present invention is generally concerned with antifouling agents anduses thereof.

BACKGROUND

Biofouling is a process in which organisms and their by-products encrusta surface. In the case of bacteria, this process leads to the formationof a well-defined bacterial network, termed biofilm. Biofilms providethe bacteria with superior survival properties under exposure toantibiotics. Biofilm formation on medical devices and implants leads tosevere infection which may result in patient death.

The attachment of marine organisms to ships and other marine devices isa major issue in the marine industry as organisms such as barnacles andmarine mussels form a thick heavy biolayer on the surface of the device.This added weight causes delay in transportation and a higherconsumption of fuel. In addition, colonization of ship hulls has beenlinked to two major environmental pollutions which are emission of gases(CO₂CO, SO₂, and NOx) into the atmosphere and the introduction ofinvasive species to marine habitats.

Other industries using water in their processes, for example coolingtowers and turbines, struggle constantly with biofouling buildup andclogging of pipes.

Biofouling initiates with the adsorption of proteins and polysaccharidesonto a substrate, therefore many antifouling approaches aim to avoidbiofouling by preventing protein adsorption or its degradation. Theseapproaches include both chemical and topographical modification of asurface.

Antifouling materials prevent organisms from attaching to a surface. Thechallenges in designing such materials are in the ability to synthesizea material that prevents the attachment of the organism to the surface,performing in an authentic environment, and meanwhile does not have aneffect on its surrounding environment by releasing toxic molecules.Antifouling materials such as paints and metal nanoparticles prevent theattachment of these organisms to a substrate, but they are toxic andharmful to the environment.

Immobilizing PEG is one of the most commonly used approaches to impartprotein resistance to a surface. The antifouling properties of PEG-basedcoatings have been widely known. The physical adsorption or covalentattachment of PEG chains cannot usually reduce protein adsorption belowa certain limit because of steric factors that limit the density of theattached polymer chains. In addition, PEG has a high tendency to undergoautoxidation.

Physical approaches to antifouling include the use of UV andultrasonication treatments of the substrate.

SUMMARY OF THE INVENTION

High quality antifouling materials are desirable as they provide a goodsolution to biofouling processes and formation of biofilms on a surface.Conventional antifouling materials present several drawbacks, as many ofthese antifouling materials are toxic (or release of toxic materials tothe environment), instable, inefficient or are limited in preventing (orcomplete diminishing) biofouling, expensive and produced via complicatedmanufacturing processes which at times require expensive equipment fortheir manufacture.

The inventors of the present invention have developed a family of noveland highly improved antifouling materials which spontaneouslyself-assemble on a surface, and which effectively prevent, diminish ordecrease fouling of the surface. The self assembly, which enables theformation of an ordered film or as active particulate materials, is madepossible by the bifunctional nature of the materials. This directed selfassembly permits formation of an ordered film or layer of thebifunctional materials which possesses a high density of antifoulingmoieties extending outwards from the surface of the material.

In one aspect of the invention, there is provided a compound comprisingat least one antifouling moiety (or group) and at least onesurface-adsorbing moiety (or group), wherein the at least oneantifouling moiety is selected amongst fluorine (—F) and a groupcomprising a fluorine atom and said at least one surface-adsorbingmoiety is selected amongst 3,4-dihydroxy-L-phenylalanin (DOPA) and DOPAcontaining groups.

In another aspect, there is provided a bifunctional compound comprisingat least one antifouling moiety (or group) and at least onesurface-adsorbing moiety (or group),

wherein the at least one antifouling moiety is selected amongst fluorine(—F) and a group comprising a fluorine atom and said at least onesurface-adsorbing moiety is selected amongst dihydroxy-amino acid anddihydroxy-amino acid containing groups,

said at least one antifouling moiety and said at least onesurface-adsorbing moiety being associated to each other via a covalentbond or via a linker group, as defined hereinbelow. In another aspect,there is provided a bifunctional compound comprising at least oneantifouling moiety (or group) and at least one surface-adsorbing moiety(or group),

wherein the at least one antifouling moiety is selected amongst fluorine(—F) and a group comprising a fluorine atom and said at least onesurface-adsorbing moiety is selected amongst3,4-dihydroxy-L-phenylalanin (DOPA) and DOPA containing groups,

said at least one antifouling moiety and said at least onesurface-adsorbing moiety being associated to each other via a covalentbond or via a linker group, as defined hereinbelow.

In another aspect, there is provided an antifouling material comprisingat least one antifouling moiety (or group) and at least onesurface-adsorbing moiety (or group),

wherein the at least one antifouling moiety is selected amongst fluorine(—F) and a group comprising a fluorine atom and said at least onesurface-adsorbing moiety is selected amongst3,4-dihydroxy-L-phenylalanin (DOPA) and DOPA containing groups,

said at least one antifouling moiety and said at least onesurface-adsorbing moiety being associated to each other via a covalentbond or via a linker group, as defined hereinbelow. In another aspect,there is provided a compound of the general formula A-L-F, wherein A isa surface-adsorbing moiety, L is a covalent bond or a linker moietylinking A and F, and F is an antifouling moiety, and wherein each of A,L and F are associated to each other as provided in the above formulavia a non-hydrolysable bond. In some embodiments, the non-hydrolysablebond is a covalent bond.

In some embodiments of any of the invention various aspects, thecompound of the invention is an antifouling agent capable of preventingor arresting adsorption of organic and/or bio-organic materials(polymers) to a surface (an article's surface).

In some embodiments, the compound of the invention is an antifoulingagent capable of preventing or arresting adsorption of proteins and/or(poly)saccharides and/or (poly)lipids to a surface.

In yet further embodiments, the compound of the invention is anantifouling agent capable of preventing or arresting adsorption ofsecretion products of cells of multi-cellular organisms or ofmicroorganisms to a surface.

In yet further embodiments, the compound of the invention is anantifouling agent capable of preventing or arresting adsorption of cellsof multi-cellular organisms or of micro-organisms to a surface, asfurther detailed hereinbelow.

The surface-adsorbing moiety being DOPA or a DOPA containing moiety isselected to adhere to or associate with a surface or a region of asurface which protection against fouling is desired. The term“associate” or “adhere” as used herein refers to any physical orchemical interaction to be formed between the DOPA group or any atomthereof, or any DOPA containing moiety or any atom thereof, and asurface region. The association may be via Van-der-Walls, coordinative,covalent, ionic, electrostatic, dipole-dipole, or hydrogen association(bond or interaction).

Independent on the actual nature of the surface-adsorbing group, namelywhether it is DOPA or a DOPA derivative, and whether association occursvia a single atom or group or via multiple atoms or groups of atoms, thesurface-adsorbing moiety (element) is capable of adhering and/or capableof maintaining the surface adherence to any surface material as definedhereinbelow. The surface adherence may be maintained even under non-dryconditions such as under aquatic environment, and also under harsherconditions such as high salt concentrations.

In some embodiments, the compounds of the invention comprise one or moreDOPA or DOPA containing groups. As known, DOPA comprises two hydroxyl(—OH) groups. Without wishing to be bound by theory, it is believed thatsurface adsorption occurs via one or both of said hydroxyl groups. Insome embodiments, the DOPA group or a moiety comprising said DOPA may bemodified to comprise one or more additional hydroxyl groups.

In some embodiments, the surface-adsorbing moiety is DOPA or a moietycomprising DOPA. In some embodiments, the moiety comprising DOPA is anorganic material selected from amino acids and aliphatic materials. Insome embodiments, the organic material is an amino acid. In anotherembodiment, the material is a peptide.

In some embodiments, the surface-adsorbing moiety is DOPA being linked,associated or bonded to an atom along the linker moiety L, as furtherdefined herein.

In some embodiments, the compound comprising a DOPA unit as well as atleast one additional hydroxylated moiety. The hydroxylated moiety may beselected amongst mono-, di-, tri-, tetra- or multiply-hydroxylatedalkyls and aryl groups and hydroxylated amino acids.

The linker moiety L associating the surface adsorbing moiety and theantifouling moiety may have a backbone structure to which bothfunctional moieties are bonded or with which they are associated. Insome embodiments, the backbone structure is further substituted bypendent groups as explained hereinbelow. The backbone structure may becomposed of carbon atoms and may include one or more heteroatoms such asN, O, S, and P atoms.

In some cases, the linker moiety may not be necessary as the twofunctional moieties may be associated or bonded directly to each other.Thus, in some embodiments, the linker moiety is absent or is a bondassociating the two functional moieties (the bond being selected fromcovalent and ionic bonds).

In some embodiments, where the linker moiety is present its backbone maycomprise one or more carbon atoms. The shortest backbone may be aone-carbon chain.

In some embodiments, the linker backbone may be selected fromsubstituted or unsubstituted carbon chain which may be saturated orunsaturated, having only single bonds, hydrocarbons comprising one ormore double bonds, or one or more triple bonds, or comprising any one ormore functional groups which may be pendent to the backbone moiety or asan interrupting group (being part of the backbone).

In some embodiments, the backbone comprises one or more inner-chain arylgroups.

In some embodiments, the linker moiety is an organic backbone moietyselected from substituted or unsusbtituted oligomer (having between 2and 11 repeating units) or polymer (having at least 12 repeating units).

In some embodiments, the linker moiety is an organic backbone moietyselected from amino acids and peptides.

In some embodiments, the backbone may comprise between 1 to 40 carbonatoms or hydrocarbon groups or any heteroatom which is positioned alongthe backbone (in the main chain). In some embodiments, the backbonecomprises between 1 to 20 carbon atoms. In some embodiments, thebackbone comprises between 1 to 12 carbon atoms. In some embodiments,the backbone comprises between 1 to 8 carbon atoms. In some embodiments,the backbone comprises 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22or 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 or 31 or 32 or 33 or 34or 35 or 36 or 37 or 38 or 39 or 40 carbon atoms.

In some embodiments, the linker moiety is constructed of a predeterminednumber of repeating units which may or may not be randomly structuredalong the backbone. The linker moiety may be substituted by one or morefunctional groups such as substituted or unsubstituted alkyl,substituted or unsubstituted alkenyl, substituted or unsubstitutedalkynyl, substituted or unsubstituted cycloalkyl, substituted orunsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl,substituted or unsubstituted aryl, substituted or unsubstitutedheteroaryl, substituted or unsubstituted heterocyclyl, substituted orunsubstituted —NR₁R₂, substituted or unsubstituted —OR₃, substituted orunsubstituted —SR₄, substituted or unsubstituted —S(O)R₅, substituted orunsubstituted alkylene-COOH, and substituted or unsubstituted ester.Each of the abovementioned groups is as defined hereinebelow.

The variable group denoted by “R” (including any one of R₁, R₂, R₃, R₄,R₅) refers to one or more group selected from hydrogen, alkyl, alkenyl,alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl,heterocyclyl, halogen, alkylene-COOH, ester, —OH, —SH, and —NH₂, asdefined herein or any combination thereof.

Each of the abovementioned groups, as indicated, may be substituted orunsubstituted. The substitution may also be by one or more R, selectedfrom hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl,cycloalkynyl, aryl, heteroaryl, heterocyclyl, halogen, alkylene-COOH,ester, —OH, —SH, and —NH₂. In some embodiments, the number of R groupsmay be 0 or 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 20.

In some embodiments, backbone chain comprises one or more heteroatom(e.g., N, O, S and P). In some embodiments, backbone chain comprisesinner-chain ester and/or carbonyl and/or amine group and/or amide group.

In some embodiments, the backbone chain is of the general structure

wherein

each * denotes a point of connectivity;

n is between 0 and 40; and

m is between 1 and 40.

In some embodiments, n is between 1 and 12. In some embodiments, n isbetween 1 and 8. In some embodiments, n is between 1 and 6.

In some embodiments, m is between 1 and 20. In some embodiments, m isbetween 1 and 12. In some embodiments, m is between 1 and 8. In someembodiments, m is between 1 and 6.

In some embodiments, one or more of the (CH₂)_(n) groups aresubstituted. In some embodiments the substitution group is a substitutedor unsubstituted phenyl. In some embodiments, the substitution group ishydroxylated or fluorinated phenyl.

In some embodiments, the backbone chain comprises an amino acid groups,and thus in the above general formula of a representative linkerbackbone, the repeating unit is an α- or β-amino acid (wherein n is 1,or n is 2, respectively).

In some embodiments, the linker moiety L is an amino acid or a peptidecomprising 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25or 26 or 27 or 28 or 29 or 30 or 31 or 32 or 33 or 34 or 35 or 36 or 37or 38 or 39 or 40 amino acids.

In some embodiments, the compounds of the invention are constructed oftwo amino acids bonded to each other via an amide bond (constituting thelinker L), wherein one amino acid is DOPA and the other is a fluorinatedamino acid, as described herein. In some embodiments, the compounds areconstructed of two amino acids: DOPA and a fluorinated amino acid, saidtwo amino acids being associated to each other via a linker moiety asdescribed herein. In some embodiments, the linker moiety is one or moreamino acid.

In some embodiments, the backbone comprises one or more surfaceadsorbing moieties and one or more antifouling moieties.

In some embodiments, the backbone comprises 1 or 2 or 3 or 4 or 5 or 6or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or19 or 20 surface-adsorbing moieties. In some embodiments, the backbonecomprises 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 antifouling moieties.

In some embodiments, the antifouling moieties are bonded to the backboneat one end and the surface-adsorbing moieties at the other end of thebackbone. In other embodiments, the antifouling moieties and thesurface-adsorbing moieties are at alternating positions along thebackbone. In other embodiments, the antifouling moieties and thesurface-adsorbing moieties are randomly positioned along the backbone.

In some embodiments, the backbone comprises one or more amino acidsunits or hydrocarbon units, the backbone having a plurality ofsurface-adsorbing moieties and a plurality of antifouling moieties,wherein the distance between two moieties, either surface-adsorbing orantifouling moieties, does not exceed 12 units, 6 units, 3 units or 1 to5 units.

In some embodiments, the backbone comprises or consists a peptide of twoor more amino acids. In some embodiments, the compounds of the inventionare peptides having at least two amino acids, at least one DOPA and atleast fluorinated group, which may or may not be a fluorinated aminoacid.

In some embodiments, the peptide comprises between 2 and 40 amino acids.In some embodiments, the peptide comprises between 2 and 20 amino acids.In some embodiments, the peptide comprises between 2 and 12 amino acids.In some embodiments, the peptide comprises between 2 and 8 amino acids.In other embodiments, the peptide comprises between 2 and 6 amino acids,or between 2 and 4 amino acids, or has 2 or 3 amino acids. In someembodiments, the peptide comprises 2, or 3, or 4, or 5, or 6, or 7, or 8or 9 or 10 or 11 or 12 amino acids.

In some embodiments, the compounds of the invention are peptides, asdefined, having at least one surface-adsorbing amino acid and at leastone antifouling amino acid. Where the peptide is constructed of twoamino acids, one of which is an antifouling amino acid and the other isa surface-adsorbing amino acid. Wherein the number of amino acids in thepeptide is greater than 2, the number of each type of amino acids may bevaried in accordance with the target final use.

As known in the art, a “peptide” comprises amino acids, typicallybetween 2 and 40, or between 2 and 20, or between 2 and 12 or between 2and 8; each amino acid being bonded to a neighboring amino acid via apeptide (amide) bond. The peptidic backbone may be modified such thatthe bond between the N— of one amino acid residue to the C— of the nextamino acid residue is altered to non-naturally occurring bonds byreduction (to —CH₂—NH—), alkylation (e.g., methylation) on the nitrogenatom, or the bonds replaced by amidic bond, urea bonds, sulfonamidebond, etheric bond (—CH₂—O—), thioetheric bond (—CH₂—S—), or —CS—NH. Thepeptide may further comprise one or more non-amino acid group.

The “amino acid” may be any natural or unnatural amino acid, an aminoacid analog, α- or β-forms, or may be in either L- or D configurations.Amino acid analogs which may be used in a compound of the invention bechemically modified at either or both of their C-terminal and/orN-terminal; or chemically modified at a side-chain functional group(e.g., positioned at the α-position or any other pendant group).

The amino acid may be selected amongst alanine, arginine, asparagine,aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine,isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tryptophan, tyrosine valine, pyrrolysine and selnocysteine;and amino acid analogs such as homo-amino acids, N-alkyl amino acids,dehydroamino acids, aromatic amino acids and α,α-disubstituted aminoacids, e.g., cystine, 5-hydroxylysine, 4-hydroxyproline, a-aminoadipicacid, a-amino-n-butyric acid, 3,4-dihydroxyphenylalanine, homoserine,α-methylserine, ornithine, pipecolic acid, ortho, meta orpara-aminobenzoic acid, citrulline, canavanine, norleucine, d-glutamicacid, aminobutyric acid, L-fluorenylalanine, L-3-benzothienylalanine andthyroxine.

In some embodiments, the amino acids are selected amongst aromatic aminoacids. Non-limiting examples of aromatic amino acids include tryptophan,tyrosine, naphthylalanine, and phenylalanine. In some embodiments, theamino acids are phenylalanine or derivatives thereof.

In some embodiments, the phenylalanine derivatives is4-methoxy-phenylalanine, 4-carbamimidoyl-1-phenylalanine,4-chloro-phenylalanine, 3-cyano-phenylalanine, 4-bromo-phenylalanine,4-cyano-phenylalanine, 4-hydroxymethyl-phenylalanine,4-methyl-phenylalanine, 1-naphthyl-alanine, 3-(9-anthryl)-alanine,3-methyl-phenylalanine, m-amidinophenyl-3-alanine, phenylserine,benzylcysteine, 4,4-biphenylalanine, 2-cyano-phenylalanine,2,4-dichloro-phenylalanine, 3,4-dichloro-phenylalanine,2-chloro-penylalanine, 3,4-dihydroxy-phenylalanine, 3,5-dibromotyrosine,3,3-diphenylalanine, 3-ethyl-phenylalanine, 3,4-difluoro-phenylal anine,3-chloro-phenylalanine, 3-chloro-phenylalanine, 2-fluoro-phenylalanine,3-fluoro-phenylalanine, 4-amino-L-phenylalanine, homophenylalanine,3-(8-hydroxyquinolin-3-yl)-1-alanine, 3-iodo-tyrosine, kynurenine,3,4-dimethyl-phenylalanine, 2-methyl-phenylalanine, m-tyrosine,2-naphthyl-alanine, 5-hydroxy-1-naphthalene, 6-hydroxy-2-naphthalene,meta-nitro-tyrosine, (beta)-beta-hydroxy-1-tyrosine,(beta)-3-chloro-beta-hydroxy-1-tyrosine, o-tyrosine,4-benzoyl-phenylalanine, 3-(2-pyridyl)-alanine, 3-(3-pyridyl)-alanine,3-(4-pyridyl)-alanine, 3-(2-quinolyl)-alanine, 3-(3-quinolyl)-alanine,3-(4-quinolyl)-alanine, 3-(5-quinolyl)-alanine, 3-(6-quinolyl)-alanine,3-(2-quinoxalyl)-alanine, styrylalanine, pentafluoro-phenylalanine,4-fluoro-phenylalanine, phenylalanine, 4-iodo-phenylalanine,4-nitro-phenylalanine, phosphotyrosine, 4-tert-butyl-phenylalanine,2-(trifluoromethyl)-phenylalanine, 3-(trifluoromethyl)-phenylalanine,4-(trifluoromethyl)-phenylalanine, 3-amino-L-tyrosine,3,5-diiodotyrosine, 3-amino-6-hydroxy-tyrosine, tyrosine,3,5-difluoro-phenyl alanine and/or 3-fluorotyrosine

In some embodiments of the invention, the compounds are peptides havingone or more surface-adsorbing amino acids grouped at the C-terminal ofthe peptide, and one or more antifouling amino acids grouped at theN-terminal of the peptide. In other embodiments, the surface-adsorbingamino acids are grouped at the N-terminal of the peptide, and theantifouling amino acids are grouped at the C-terminal of the peptide.

In some embodiments, at least one surface-adsorbing amino acids ispositioned at one of the peptide termini (either the C-terminal or theN-terminal), and at least one antifouling amino acids is positioned atthe other of the peptide termini.

In some embodiments, the at least one surface-adsorbing amino acids ispositioned at a midpoint position between the C-terminal of the peptideand the N-terminal of the peptide, and one or more antifouling aminoacids are positioned each at each of the peptide termini.

In some embodiments, the peptide may comprise any one or more aminoacids along the chain, e.g., positioned between the termini functionalamino acids, positioned randomly along the peptide or at specificpositions thereof in order to affect one or more additional structuralor functional attributes. In some embodiments, the one or more aminoacids may or may not be aromatic amino acids.

The end C- or N-termini of the peptide may be modified to affect ormodulate (increase or decrease or generally change) one or more propertyof the peptide, e.g., a structural change,hydrophobicity/hydrophilicity, charge, solubility, surface adhesion,toxicity to organisms, biocompetability, resistance to degradation ingeneral and enzymatic degradation in particular and others. The C- orN-termini of the peptide may be chemically modified by forming an ester,an amide, or any other functional group at the desired position; suchthat the peptides may have an amine at one end thereof (the N-terminal)and a carboxyl group (the C-terminal) at the other end, or may haveothers groups at either of the termini.

The antifouling moiety renders compounds of the invention with theantifouling and anti-biofilms properties discussed herein. In someembodiments, in a compound of the invention, the antifouling moiety is afluorine atom. In some embodiments, the antifouling moiety is afluorinated moiety or substituent (a group comprising a fluorine atom).In some embodiments, the antifouling moiety comprises a C—F group.

In some embodiments, the antifouling moiety comprises one or morefluorine atoms and/or fluorinated moieties. In some embodiments, theantifouling moiety comprises 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20fluorine atoms and/or fluorinated moieties. In some embodiments, theantifouling moiety is perfluorinated.

In some embodiments, the antifouling element is a fluorinated organicgroup. In some embodiments, the fluorinated organic group isF-substituted carbon group having a C—F bond, wherein the number of C—Fbonds in the group may be one or more. In some embodiments, theantifouling moiety comprises 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9or 10 fluorine atoms. In some embodiments, the fluorinated carbon groupcomprises or consists —CF, —CF₂, and —CF₃. In some embodiments, thefluorinated carbon group comprises multiple —CF or —CF2 groups.

In some embodiments, the fluorinated carbon group is a substituted orunsubstituted alkyl. In some embodiments, the antifouling moiety is analkyl comprising 1 or 2 or 3 or 4 or 5 or 6 fluorine atoms. In someembodiments, the antifouling moiety is an alkyl having at least onefluorine atom on each carbon atom.

In other embodiments, the antifouling moiety is a fluorinatedsubstituted or unsubstituted aryl. In some embodiments, the arylcomprises 1 or 2 or 3 or 4 or 5 fluorine atoms. In some embodiments, thearyl is perfluorinated.

In other embodiments, the aryl is a phenyl group. In other embodiments,the aryl is a heteroaryl group.

In some embodiments, the antifouling moiety comprises or consists one ormore fluorinated amino acid moieties.

In some embodiments, the fluorinated amino acid, wherein the amino acidis as defined herein, is a fluorinated phenylalanine derivative, whereinthe fluoride atom substitutes one or more phenyl ring positions. Thesubstitution on the phenyl ring may be at the ortho, meta and/or parapositions. The number of fluoride atoms may be 1, 2, 3, 4, or 5.

In some embodiments, the fluorinated phenylalanine is selected fromo-fluorophenylalanine, m-fluorophenylalanine and p-fluorophenylalanine.

In some embodiments, the compound of the invention is a peptide whichcomprises between 2 and 12 or between 2 and 8 amino acids, each aminoacid being selected from aromatic amino acids. In some embodiments, thepeptide comprises DOPA. In other embodiments, the peptide comprises afluorinated aromatic amino acid selected from o-fluorophenylalanine,m-fluorophenylalanine and p-fluorophenylalanine.

In some embodiments, the compound of the invention is a peptidecomprising DOPA at one termini and a fluorinated aromatic amino acidselected from o-fluorophenylalanine, m-fluorophenylalanine andp-fluorophenylalanine at the other termini.

In some embodiments, the compound of the invention is a peptidecomprising DOPA at a mid-point amino acid along the peptide and afluorinated aromatic amino acid selected from o-fluorophenylalanine,m-fluorophenylalanine and p-fluorophenylalanine at the each of thepeptide termini.

In some embodiments, the antifouling moiety of compounds of theinvention constitute two antifouling amino acid residues, optionallybonded to each other. In some embodiments, the antifouling moietyconstitutes two fluorinated amino acid residues, optionally bonded toeach other. In some embodiments, the antifouling moiety constitutes atleast two fluorinated amino acid residues, each being optionally bondedto the other.

As sated herein, compounds of the invention are generally bifunctionalcompounds which in some embodiments are used as antifouling agents forachieving inter alfa one or more of the following:

preventing or arresting or minimizing or diminishing adsorption oforganic and/or bio-organic materials (polymers) to a surface (anarticle's surface);

preventing or arresting or minimizing or diminishing adsorption ofproteins and/or (poly)saccharides and/or (poly)lipids to a surface;

preventing or arresting or minimizing or diminishing secretion fromcells of multi-organism or of micro-organisms onto a surface; and

preventing or arresting or minimizing or diminishing adsorption of cellsof multi-organism or micro-organisms to a surface.

The compounds of the invention are capable of endowing a surface withwhich they are associated with the above attributes as they are capableof associating intimately with said surface region, and at the same timecapable of forming a dense layer of exposed antifouling moieties whichcoat or film the surface region, thereby forming a protective coat,layer or film thereon. The compounds of the invention, in particular,the peptide of the invention comprise elements, in particular aromaticgroups or aromatic amino acids which enable self-assembly of thecompounds into ordered structures having specific directionality.Without wishing to be bound by theory, an ideal configuration for theself-assembled peptides result in a film as exemplary depicted in FIG.1.

Thus, compounds of the invention may be of any structure as shown inScheme 1 below.

The 6 exemplary structures of compounds shown in Scheme 1, the generalstructure A-L-F is shown, wherein A is a surface-adsorbing moiety, L isa covalent bond or a linker moiety linking A and F, and F is anantifouling moiety, and wherein each of A, L and F are associated toeach other as provided in the above structures via a non-hydrolysablebond(s). Each of A, L and F are as defined hereinabove.

As depicted in Structure I, the linker L may be a linear orsubstantially linear structure having at one end a surface-adsorbingmoiety A and at the other end an antifouling moiety F, wherein L mayoptionally be substituted. L may be a long or short linker moiety. L maybe absent. Where L is present, it comprises at least one carbon atom.

In Structure II, the linker L associates a single surface-adsorbingmoiety A with two antifouling moieties F. There may be in someembodiments, more than two antifouling moieties, each of which extendingoutwards away from the surface. While in Structure II the linker isbifurcated to provide two linking points, one for each antifoulingmoiety, the connectivity of the plurality of antifouling moieties mayalternatively be along the backbone chain of the linker. In other words,the two antifouling moieties need not have a common bonding atom orgroup.

In Structure III, the linker L associates two surface-adsorbing moietiesA with an antifouling moiety F. There may be in some embodiments, morethan one antifouling moiety. While in Structure III the linker isbifurcated to provide two linking points, one for each surface-adsorbingmoiety, the connectivity of the plurality of surface-binding moietiesmay alternatively be along the backbone chain of the linker. In otherwords, the two surface-binding moieties need not have a common bondingatom or group.

In Structure V a surface-adsorbing moiety A is positioned substantiallymid-way on the backbone of the linker L with two linker arms extendingtherefrom, at the end of which an antifouling moiety is provided.Similarly, in Structure VI, two surface-adsorbing moieties are providedto link a single antifouling moiety.

The compounds of the invention may also be constructed to have longerlinker backbones, with a plurality of surface-binding moieties andantifouling moieties positioned along the backbone to provide a morecompact covering of a surface region. One such exemplary embodiments ofcompounds of the invention is depicted in Structure IV of Scheme 1.

In some embodiments, the compounds depicted in the Structures of Scheme1 are each aliphatic compounds (L being an aliphatic backbone) havingone or more antifouling (F) and surface-adsorbing (A) moieties.

In some embodiments, the linker backbone is a peptide.

Exemplary, non-limiting examples of compounds according to the inventionare Peptides herein designated Peptide 1-18.

Peptides of Group I are exemplified in non-limiting compounds of theinvention designated Peptides 1-4.

A perfluorinated derivative is designated Peptide 5.

A dipeptide derivative is designated Peptide 6.

Peptides of Group II are exemplified in non-limiting compounds of theinvention designated Peptides 7-10.

Peptides of Group III are similarly encompassed by the presentinvention. Exemplary compounds are designated Peptides 11-14:

Similarly to Peptides 1 to 14 depicted above other peptides of theinvention may comprise surface binding amino acids in a greater number(amount) as compared to the number of antifouling amino acids, e.g.,fluorinated aromatic amino acids; such compounds having the structuredepicted below for Group Peptide IV and V:

Additional non-limiting peptides according to the invention include:NH₂-L-DOPA-L-(4-F)-Phe-COOH  Peptide 15NH₂-L-DOPA-D-(4-F)-Phe-COOH  Peptide 16NH₂-L-DOPA-L-(4-F)-Phe-L-(4-F)-Phe-COOMe  Peptide 17.

As used above, the designation “(4-F)—” refers to para-fluoroderivatives.

As used above, the compounds of the invention may have one or moresubstituents on any of the atom thereof. In the compounds as defined:

“alkyl”, “alkenyl” and “alkynyl” carbon chains, if not specified, referto carbon chains each containing from 1 to 20 carbons, or 1 or 2 to 16carbons, and are straight or branched. Each such group may besubstituted. In some embodiments, the carbon chain contains 1 to 10carbon atoms. In some embodiments, the carbon chain contains 1 to 6carbon atoms. In some embodiments, the carbon chain contains 2 to 6carbon atoms. Alkenyl carbon chains may contain from 2 to 20 carbons, or2 to 18 carbons, or 2 to 16 carbons, or 2 to 14 carbons, or 2 to 12carbons, or 2 to 10 carbons, or 2 to 8 carbons, or 2 to 6 carbons, or 2to 4 carbons. The alkenyl carbon chain may similarly contain 1 to 8double bonds, or 1 to 7 double bonds, or 1 to 6 double bonds, or 1 to 5double bonds, or 1 to 4 double bonds, or 1 to 3 double bonds, or 1double bond, or 2 double bonds. Alkynyl carbon chains from 2 to 20carbons, or 2 to 18 carbons, or 2 to 16 carbons, or 2 to 14 carbons, or2 to 12, or carbons 2 to 10 carbons, or 2 to 8 carbons, or 2 to 6carbons, or 2 to 4 carbons. The alkynyl carbon chain may similarlycontain 1 to 8 triple bonds, or 1 to 7 triple bonds, or 1 to 6 triplebonds, or 1 to 5 triple bonds, or 1 to 4 triple bonds, or 1 to 3 triplebonds, or 1 triple bond, or 2 triple bonds. Exemplary alkyl, alkenyl andalkynyl groups include, but are not limited to, methyl, ethyl, propyl,isopropyl, isobutyl, n-butyl, sec-butyl, tert-butyl, isohexyl, allyl(propenyl) and propargyl (propynyl).

“cycloalkyl” refers to a saturated mono- or multi-cyclic ring system, incertain embodiments of 3 to 10 carbon atoms, in other embodiments 3 to 6carbon atoms; cycloalkenyl and cycloalkynyl refer to mono- ormulticyclic ring systems that respectively include at least one doublebond and at least one triple bond. Cycloalkenyl and cycloalkynyl groupsmay, in some embodiments, may contain between 3 to 10 carbon atoms, infurther embodiments, between 4 to 7 carbon atoms and cycloalkynylgroups, in further embodiments, containing 8 to 10 carbon atoms. Thering systems of the cycloalkyl, cycloalkenyl and cycloalkynyl groups maybe composed of one ring or two or more rings which may be joinedtogether in a fused, bridged or spiro-connected fashion.

“aryl” refers to aromatic monocyclic or multicyclic groups containingfrom 6 to 10 carbon atoms. Aryl groups include, but are not limited togroups such as unsubstituted or substituted fluorenyl, unsubstituted orsubstituted phenyl, and unsubstituted or substituted naphthyl.

“heteroaryl” refers to a monocyclic or multicyclic aromatic ring system,in certain embodiments, of about 5 to about 15 members where one ormore, in some embodiments 1 to 3, of the atoms in the ring system is aheteroatom, that is, an element other than carbon, including e.g.,nitrogen, oxygen or sulfur. The heteroaryl group may be optionally fusedto a benzene ring. Heteroaryl groups include, but are not limited to,furyl, imidazolyl, pyrimidinyl, tetrazolyl, thienyl, pyridyl, pyrrolyl,thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, triazolyl, quinolinyl andisoquinolinyl.

“heterocyclyl” refers to a saturated mono- or multi-cyclic ring system,in one embodiment of 3 to 10 members, in another embodiment of 4 to 7members, in a further embodiment of 5 to 6 members, where one or more,in certain embodiments, 1 to 3, of the atoms in the ring system is aheteroatom, that is, an element other than carbon, including but notlimited to, nitrogen, oxygen or sulfur. In embodiments where theheteroatom(s) is nitrogen, the nitrogen is optionally substituted withalkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl,cycloalkyl, heterocyclyl, cycloalkylalkyl, heterocyclylalkyl, acyl,guanidine, or the nitrogen may be quaternized to form an ammonium groupwhere the substituents are selected as above.

“—NR₁R₂” refers to an amine group wherein R₁ and R₂ are independentlyselected from hydrogen, alkyl, alkenyl, alkenyl, cycloalkyl,cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heterocyclyl, ester andcarbonyl, each as defined herein or alternatively known in the art.

“—OR₃” refers to a hydroxyl group or an alkoxy group or derivative,wherein R₃ is selected from hydrogen, alkyl, alkenyl, alkenyl,cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heterocyclyl,halogen, sulfinyl, ester and carbonyl.

“—SR₄” refers to a thiol group or a thioether group or derivative,wherein R₄ is selected from hydrogen, alkyl, alkenyl, alkenyl,cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heterocyclyl,halogen, sulfinyl, ester and carbonyl.

“—S(O)R₅” refers to a sulfinyl group, wherein R₅ is selected fromhydrogen, alkyl, alkenyl, alkenyl, cycloalkyl, cycloalkenyl,cycloalkynyl, aryl, heteroaryl, heterocyclyl, halogen, sulfinyl, esterand carbonyl.

“ester” refers to —C(O)OR₈ in which R₈ is selected from hydrogen, alkyl,alkenyl, alkenyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl,heteroaryl, heterocyclyl, halogen, —NR₁R₂, sulfinyl, carbonyl, —OR₃,SR₄, —S(O)R₅—OH, —SH and —NH.

The term “substituted” refers to any group or any ligand as definedherein above having (further substituted) one or more substituent,wherein the substituent is a ligand as defined herein above. In someembodiments, the substituent is selected from alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl, heterocyclyl,halogen, alkylene-COOH, ester, —OH, —SH, and —NH. In some embodiments,the number of substituents on a certain ligand is 0 or 1 or 2 or 3 or 4or 5 or 6 or 7 or 8 or 9 or 20 substituents.

The compounds of the invention (e.g., peptide) have been manufacturedaccording to known methods in the art. In some embodiments, thecompounds have been synthesized using solid or solution phase synthesis.

The antifouling compounds of the invention may be formulated asready-for-use products or as concentrates. The ready-for-use productsmay be in the form of powders, oil preparations (or dispersions),emulsions or aerosol formulations. The formulations comprising one ormore compounds of the invention, in particular peptides of theinvention, may comprise additional components, such as fixatives,co-solvents, plasticizers, dyes, color pigments, corrosion inhibitors,chemical stabilizers or any other additive.

The formulation and/or compounds may be applied by any method known inthe art including brushing, spraying, roll coating, dipping, spincoating, dispensing, printing, ink-jet printing, stamping, drop castingand any combination thereof.

In another aspect, the invention provides a film comprising a compoundaccording to the present invention.

In some embodiments, the film is obtainable by self-assembly of thecompounds onto a surface, as discussed herein.

In some embodiments, the film comprises a peptide according to theinvention.

In some embodiments, the film is antifouling and/or anti-biofilm.

The film may be a continuous film or comprise separate regions ordomains. The number of different antifouling compounds in the film maybe determined inter alia by the physical limit of the number ofmaterials that may be put on a desired area, the chemical or physicalnature of the compounds, and others.

In another aspect, the invention also provides use of at least onecompound according to the invention for forming a film according to theinvention.

The invention also provides a surface or an article (or device), whereinat least a region thereof is coated with an antifouling film accordingto the present invention.

The article or device may be any article, wherein antifouling propertiesare desired. Typically, the article is an article which experienceshumidity or aquatic environments. The article or device may be anysurface region of a marine vessel and/or a hull of a marine vesseland/or a medical device and/or a contact lens and/or a food processingapparatus and/or a drinking water dispensing apparatus and/or a pipelineand/or a cable and/or a fishing net and/or a pillar of a bridge and/or asurface region of a water immersed article, and/or others.

The adsorption properties of compounds of the invention areexceptionally improved and therefore, a film thereof may be formed onany surface material. The substrate may be of a flexible or rigidsubstrate, which may be substantially two-dimensional (a thin flatarticle) or three-dimensional. The surface of the article can be of anysmoothness.

The surface may be selected, in a non-limiting fashion, from outdoorwood work, external surface of a central heating or cooling system,bathroom walls, hull of a marine vessel or any off-shore installations,surfaces in food production/packaging, surfaces in any industrialfacility, surfaces in any medical facility, surfaces in any waterfacility surface of a device, surface of an electronic device, screenssurfaces, touch screen surfaces, non-touch screens and others. Thesurface material (of the article) may be any material selected fromwood, glass, mica, plastics, ceramics, cement, metals, semiconductors,silicon surfaces (e.g., silicon wafer, a silicon wafer with a 100 nmtitanium layer), carbon, hybrid materials (e.g., 400 meshCopper-formvar®/carbon grids), stainless steel, metal oxides, aluminaand others.

The antifouling properties endowed by compounds of the invention arebest appreciated by the observed prevention of accumulation of organismsor organism's secretion on a variety of surfaces. The organisms thatparticipate in the fouling of surfaces in humid, salt water and freshwater environments include, for example, bacteria, diatoms, hydroids,algae, bryozoans, protozoans, ascidians, tube worms, asiatic clams,zebra mussels and barnacles. Thus, the compounds of the invention arecapable of preventing both micro- and macrofouling, e.g., prevention ofbacterial and viral adhesion as well as attachment of larger organismsor cells shed from bodies of multi cellular organisms.

In some embodiments, the compound of the invention is an antifoulingagent capable of preventing or arresting adsorption of secretionproducts of cells of muli-cellular organism or of microorganisms to asurface dialysis units to prevent adherence of blood cells or ofproteins secreted from blood cells from a patient being treated by theunit.

In some embodiments, the organisms are bacteria. In some embodiments,the bacteria being selected, in some embodiments from Bordetellapertussis, Borrelia burgdorferi, Brucella abortus, Brucella canis,Brucella melitensis, Brucella suis, Campylobacter jejuni, Chlamydiapneumonia, Chlamydia psittaci, Chlamydia trachomatis, Clostridiumbotulinum, Clostridium difficile, Clostridium perfringens, Clostridiumtetani, Corynebacterium diphtheria, Enterococcus faecalis, Enterococcusfaecium, Escherichia coli (E. coli), Enterotoxigenic Escherichia coli(ETEC), Enteropathogenic E. coli, Francisella tularensis, Haemophilusinfluenza, Helicobacter pylori, Legionella pneumophila, Leptospirainterrogans, Listeria monocytogenes, Mycobacterium leprae, Mycobacteriumtuberculosis, Mycoplasma pneumonia, Neisseria gonorrhoeae, Neisseriameningitidis, Pseudomonas aeruginosa, Rickettsia rickettsii, Salmonellatyphi, Salmonella typhimurium, Shigella sonnei, Staphylococcusepidermidis, Staphylococcus saprophyticus, Streptococcus agalactiae,Streptococcus mutans Streptococcus pneumonia, Streptococcus pyogenes,Treponema pallidum, Vibrio cholera, Vibrio harveyi and Yersinia pestis.

In some embodiments of the invention, the bacterium is Escherichia coli(E. Coli). In some embodiments of the invention, the bacterium is P.aeruginosa.

As used herein, the term “prevention” refers to the arresting, limitingor overall controlling settling, attachment, accumulation and dispersionof organisms and/or organism's secretion and/or organic and/orbio-organic material (e.g., proteins and/or (poly)saccharides and/or(poly)lipids) on a surface, prevention of biofilm formation and toaffecting its integrity (e.g., degrading it) and further growth. As aperson of skill in the art would realize, the compounds and/or films ofthe invention have the ability to prevent and control fouling of asurface by minimizing, diminishing or arresting fouling adhesion, byfoul release. Thus, the compounds and/or films of the invention maysimilarly be regarded as antimicrobial, antiviral, antifungal andcytostatic materials.

In another aspect of the invention, there is provided a method forinhibiting settling, attachment, accumulation and dispersion oforganisms and/or organism's secretion and/or organic and/or bio-organicmaterial (e.g., proteins and/or (poly)saccharides and/or (poly)lipids)on a surface, the method comprising contacting the surface with aneffective amount of a formulation comprising a compound according to theinvention (e.g., the peptide).

The invention provides a further method for inhibiting settling,attachment, accumulation and dispersion of organisms and/or organism'ssecretion and/or organic and/or bio-organic material (e.g., proteinsand/or (poly)saccharides and/or (poly)lipids) on a surface, the methodcomprising forming a film or coat or layer of a compound according tothe invention on said surface.

The invention further provides a kit comprising a compound according tothe invention and at least one solvent for dissolving or formulatingsaid compound into a deliverable form, and instructions of use.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosedherein and to exemplify how it may be carried out in practice,embodiments will now be described, by way of non-limiting example only,with reference to the accompanying drawings, in which:

FIG. 1 depicts a configuration of a film according to the invention, thefilm comprising compounds or peptides according to the invention,wherein the adsorbing elements are at one side of the film and theelements that resist fouling (antifouling elements) are at the otherside of the film.

FIG. 2 shows a general scheme for the formation of a coating on asubstrate by dip coating. An exemplary peptide is depicted as themolecular structures.

FIGS. 3A-3F show contact angle measurement of peptide 1 coated on a Tisurface in methanol (FIG. 3A), ethanol (FIG. 3B), isopropanol (FIG. 3C),acetone (FIG. D), dimethyl sulphoxide (DMSO) (FIG. 3E) and1,1,1,3,3,3-hexafluoro-2-propanol (HFP) (FIG. 3F). Concentration usedwere 0.5 mg/mL, incubation time 10 h.

FIG. 4 provides ATR-FTIR spectrum of peptide 1, dissolved in acetone(lower line), ethanol (middle line) and isopropanol (top line).

FIGS. 5A-5H show contact angle measurements of a bare and coated surfacewith peptide 1, (FIG. 5A, FIG. 5B) titanium, (FIG. 5C, FIG. 5D) gold(FIG. 5E, FIG. 5F) silicon and (FIG. 5G, FIG. 5H) stainless steel.Peptide concentration was 0.5 mg/mL, dissolved in methanol, incubationtime 10 h.

FIGS. 6A-6E show contact angle measurements of titanium surfaces coatedwith different peptides (FIG. 6A) peptide 2, (FIG. 6B) peptide 3, (FIG.6C) peptide 4, (FIG. 6D) peptide 5 and (FIG. 6E) peptide 6. Peptideconcentration was 0.5 mg/mL, dissolved in methanol, incubation time 10h.

FIGS. 7A-7C show hydrophobicity enhancement as influenced byconcentration of a peptide: Contact angle of (FIG. 7A) bare Ti surface(FIG. 7B) peptide 1 coated Ti surface at 0.5 mg/mL (FIG. 7C) peptide 1coated Ti surface at 1.0 mg/mL. Incubation time 10 h, solvent methanol.

FIGS. 8A-8G present AFM topography images of (FIG. 8A) a bare mica, anda mica substrate modified with (FIG. 8B) peptide 1 (FIG. 8C) peptide 2(FIG. 8D) peptide 3 (FIG. 8E) peptide 4 (FIG. 8F) peptide 5 and (FIG.8G) peptide 6. The scale bar represents 500 nm.

FIGS. 9A-9B present Atomic Force Microscopic (AFM) images of (FIG. 9A)bare Ti surface and (FIG. 9B) Peptide 1 coated Ti surface.

FIG. 10 presents ATR-FTIR spectra of (a) a bare Ti surface and (b) a Tisurface coated with peptide 1.

FIG. 11 presents ATR-FTIR spectra of titanium substrates coated withpeptide 2 (a), 3 (b), 4 (c) and 5 (d).

FIG. 12 presents ATR-FTIR spectrum of titanium substrate coated withpeptide 6.

FIG. 13 presents Real-time QCM-D measurement For Peptide 1. Frequency(F) and dissipation (D) change upon adsorption of peptide 1 to Tisensor. Arrows mark peptide addition (a) and washing (b).

FIGS. 14A-14E present Real-time QCM-D measurements. Frequency (blue) anddissipation (orange) changes upon adsorption of peptide (FIG. A) 2,(FIG. B) 3, (FIG. C) 4, (FIG. D) 5 and (FIG. E) 6.

FIG. 15 presents XPS analysis of a bare Ti substrate, and substratescoated with peptides 1-4.

FIG. 16 provides XPS analysis of a bare Ti substrate, and substratescoated with peptides 5-6.

FIG. 17 shows Adsorbed amounts of BSA, and Lysozyme on Ti substrates andpeptide coated Ti substrates (since the signal is very low only SD canbe shown). Standard deviations are based on three different experiments.

FIGS. 18A-18D present micrographs of crystal violet stained P.aeruginosa biofilms on control Ti (FIG. A) and on peptide coated Ti(FIG. B). (FIG. C-D) show biofilm formation reduction by peptidecoating.

FIGS. 19A-19B show images: FIG. 19A is a TEM image of a filmself-assembled on a TEM cupper grid. FIG. 19B is a SEM image of a filmformed on a silicon substrate.

DETAILED DESCRIPTION OF EMBODIMENTS

Biofouling is a process in which organisms and their by-products encrusta surface. It is one of the main concerns today in the health caresystem as the adsorption of pathogenic bacteria to medical devicescauses hospital acquired infections. In addition, it is a major problemin the marine industry since the adsorption of marine organisms on shipshull leads to an increase in the consumption of fuel and delays intransportation. Many approaches to prevent biofouling have beensuggested, however, they suffer from drawbacks such as release of toxicmaterials to the surroundings, low stability that limits their long-termapplication or complex and expensive synthesis.

The invention disclosed herein is based on the inventors development ofantifouling coatings that are spontaneously formed by the self-assemblyof a compounds such as peptides. The results presented clearly show thatthe coatings completely prevented the first stage of biofouling andabolished the adsorption of proteins to a substrate. In addition, thecoating reduced significantly the amount of bacteria on the substrate.

The invention provides a peptide comprising at least two amino acids, atleast one of said amino acids being 3,4-dihydroxy-L-phenylalanin (DOPA)and at least another of said amino acids being fluorinated.

In some embodiments, said peptide is antifouling.

In some embodiments, said fluorinated amino acid is bonded to said atleast one DOPA.

In some embodiments, the peptide comprising between 3 and 8 amino acids.In some embodiments, the peptide comprising between 2 and 8 amino acids,between 3 and 6 amino acids or between 3 and 5 amino acids.

In some embodiments, each amino acid is bonded to said another aminoacid via a peptidic bond. In some embodiments, at least two of saidamino acids are bonded to each other through a covalent linker. In someembodiments, the peptide of the invention having the general formulaA-L-F, wherein A is DOPA, L is a covalent bond or a linker moietylinking A and F, and F is a fluorinated amino acid moiety.

In some embodiments, said bond or linker associating A to L, or L to Fis a non-hydrolysable bond or linker group. In some embodiments, thelinker is selected from substituted or unsubstituted carbon chain. Insome embodiments, the linker is composed of two or more amino acids. Insome embodiments, the linker comprises between 1 to 40 carbon atoms. Insome embodiments, the linker is of the general structure

-   wherein-   each * denotes a point of connectivity;-   n is between 0 and 40; and-   m is between 1 and 40.

In some embodiments, two or more moieties are DOPA moieties. In someembodiments, the peptide comprises two or more fluorinated amino acids.In some embodiments, the peptide comprises two or more DOPA and two ormore fluorinated amino acids moieties.

In some embodiments, the peptide comprises one or more DOPA and two ormore fluorinated amino acids moieties. In some embodiments, the peptidecomprises two or more DOPA and one or more fluorinated amino acidsmoieties. In some embodiments, said amino acid being fluorinated isselected amongst natural or unnatural amino acid, an amino acid analog,α- or β-forms, and L- or D amino acids. In some embodiments, the aminoacid is selected amongst alanine, arginine, asparagine, aspartic acid,cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine,leucine, lysine, methionine, phenylalanine, proline, serine, threonine,tryptophan, tyrosine valine, pyrrolysine and selnocysteine; and aminoacid analogs such as homo-amino acids, N-alkyl amino acids, dehydroaminoacids, aromatic amino acids and α,α-disubstituted amino acids, cystine,5-hydroxylysine, 4-hydroxyproline, a-aminoadipic acid, a-amino-n-butyricacid, 3,4-dihydroxyphenylalanine, homoserine, α-methylserine, ornithine,pipecolic acid, ortho, meta or para-aminobenzoic acid, citrulline,canavanine, norleucine, d-glutamic acid, aminobutyric acid,L-fluorenylalanine, L-3-benzothienylalanine and thyroxine.

In some embodiments, the amino acid is selected amongst aromatic aminoacids. In some embodiments, the aromatic amino acids are selected fromtryptophan, tyrosine, naphthylalanine, and phenylalanine. In someembodiments, the amino acids are selected from phenylalanine and/orderivatives thereof.

In some embodiments, the phenylalanine derivatives are selected from4-methoxy-phenylalanine, 4-carbamimidoyl-1-phenylalanine,4-chloro-phenylalanine, 3-cyano-phenylalanine, 4-bromo-phenylalanine,4-cyano-phenylalanine, 4-hydroxymethyl-phenylalanine,4-methyl-phenylalanine, 1-naphthyl-alanine, 3-(9-anthryl)-alanine,3-methyl-phenylalanine, m-amidinophenyl-3-alanine, phenylserine,benzylcysteine, 4,4-biphenylalanine, 2-cyano-phenylalanine,2,4-dichloro-phenylalanine, 3,4-dichloro-phenylalanine,2-chloro-penylalanine, 3,4-dihydroxy-phenylalanine, 3,5-dibromotyrosine,3,3-diphenyl alanine, 3-ethyl-phenylalanine, 3,4-difluoro-phenylalanine,3-chloro-phenylalanine, 3-chloro-phenylalanine, 2-fluoro-phenylalanine,3-fluoro-phenylalanine, 4-amino-L-phenylalanine, homophenylalanine,3-(8-hydroxyquinolin-3-yl)-1-alanine, 3-iodo-tyrosine, kynurenine,3,4-dimethyl-phenylalanine, 2-methyl-phenylalanine, m-tyrosine,2-naphthyl-alanine, 5-hydroxy-1-naphthalene, 6-hydroxy-2-naphthalene,meta-nitro-tyrosine, (beta)-beta-hydroxy-1-tyrosine,(beta)-3-chloro-beta-hydroxy-1-tyrosine, o-tyrosine,4-benzoyl-phenylalanine, 3-(2-pyridyl)-alanine, 3-(3-pyridyl)-alanine,3-(4-pyridyl)-alanine, 3-(2-quinolyl)-alanine, 3-(3-quinolyl)-alanine,3-(4-quinolyl)-alanine, 3-(5-quinolyl)-alanine, 3-(6-quinolyl)-alanine,3-(2-quinoxalyl)-alanine, styrylalanine, pentafluoro-phenylalanine,4-fluoro-phenylalanine, phenylalanine, 4-iodo-phenylalanine,4-nitro-phenylalanine, phosphotyrosine, 4-tert-butyl-phenylalanine,2-(trifluoromethyl)-phenylalanine, 3-(trifluoromethyl)-phenylalanine,4-(trifluoromethyl)-phenyl alanine, 3-amino-L-tyrosine,3,5-diiodotyrosine, 3-amino-6-hydroxy-tyrosine, tyrosine,3,5-difluoro-phenylalanine and 3-fluorotyrosine.

In some embodiments, said fluorinated amino acid are selected fromo-fluorophenylalanine, m-fluorophenylalanine and p-fluorophenyl alanine.

In some embodiments, the peptide comprises between 2 and 12 amino acids,each amino acid being selected from aromatic amino acids. In someembodiments, the peptide comprises DOPA at one termini and a fluorinatedaromatic amino acid selected from o-fluorophenylalanine,m-fluorophenylalanine and p-fluorophenylalanine at the other termini. Insome embodiments, the peptide comprises DOPA at a mid-point amino acidalong the peptide and a fluorinated aromatic amino acid selected fromo-fluorophenylalanine, m-fluorophenylalanine and p-fluorophenylalanineat each of the peptide termini.

In some embodiments, the peptide is for use as an antifouling agent;e.g., for preventing or arresting or minimizing or diminishing one ormore of the following:

(a) adsorption of organic and/or bio-organic materials to a surface;

(b) adsorption of proteins and/or (poly)saccharides and (poly)lipids toa surface;

(c) secretion from cells of multi-organism or of micro-organisms onto asurface; and

(d) adsorption of cells of multi-organism or micro-organisms to asurface.

The specific compounds of the invention are selected from:

The invention also contemplates formulations comprising peptidecompounds as described herein. The formulation may be a ready-for-useantifouling formulation.

The invention also provides a film or a coat comprising at least onepeptide of the invention. The film is preferably antifouling and/oranti-biofilm.

The film may be part of an article or a device comprising at least onesurface region coated with a film according to the invention. Thearticle or device may be selected from a marine vessel, a hull of amarine vessel, a medical device, a contact lens, a food processingapparatus, a drinking water dispensing apparatus, a pipeline, a cable, afishing net, a pillar of a bridge and a surface region of a waterimmersed article.

The film in such devices or articles are for preventing biofoulingcaused by an organism selected from bacteria, diatoms, hydroids, algae,bryozoans, protozoans, ascidians, tube worms, asiatic clams, zebramussels and barnacles. In some embodiments, the organisms are bacteria.In some embodiments, the bacteria is selected from Bordetella pertussis,Borrelia burgdorferi, Brucella abortus, Brucella canis, Brucellamelitensis, Brucella suis, Campylobacter jejuni, Chlamydia pneumonia,Chlamydia psittaci, Chlamydia trachomatis, Clostridium botulinum,Clostridium difficile, Clostridium perfringens, Clostridium tetani,Corynebacterium diphtheria, Enterococcus faecalis, Enterococcus faecium,Escherichia coli (E. coli), Enterotoxigenic Escherichia coli (ETEC),Enteropathogenic E. coli, Francisella tularensis, Haemophilus influenza,Helicobacter pylori, Legionella pneumophila, Leptospira interrogans,Listeria monocytogenes, Mycobacterium leprae, Mycobacteriumtuberculosis, Mycoplasma pneumonia, Neisseria gonorrhoeae, Neisseriameningitidis, Pseudomonas aeruginosa, Rickettsia rickettsii, Salmonellatyphi, Salmonella typhimurium, Shigella sonnei, Staphylococcusepidermidis, Staphylococcus saprophyticus, Streptococcus agalactiae,Streptococcus mutans Streptococcus pneumonia, Streptococcus pyogenes,Treponema pallidum, Vibrio cholera, Vibrio harveyi and Yersinia pestis.

In some embodiments, bacteria are Escherichia coli (E. Coli). In someembodiments, the bacteria are P. aeruginosa.

The invention also provide use of a peptide according the invention forpreventing or arresting adsorption of secretion products of cells ofmuli-cellular organism or of microorganisms to a surface of a dialysisunit to prevent adherence of blood cells or of proteins secreted fromblood cells from a patient being treated by the unit.

The invention further provides a method for inhibiting settling,attachment, accumulation and dispersion of organisms, organism'ssecretion of an organic and/or bio-organic material on a surface, themethod comprising contacting the surface with an effective amount of aformulation comprising a peptide according to the invention.

In another aspect, the invention provides a film or a coat comprising acompound having at least one antifouling moiety and at least onesurface-adsorbing moiety, wherein the at least one antifouling moiety isselected amongst fluorine (—F) and a group comprising at least onefluorine atom and said at least one surface-adsorbing moiety beingselected amongst 3,4-dihydroxy-L-phenylalanin (DOPA) and DOPA containinggroups. In some embodiments, the film or coat is formed on a surfaceregion of a device or an article.

The invention also provides a film or a coat comprising a bifunctionalcompound comprising at least one antifouling moiety and at least onesurface-adsorbing moiety (or group), wherein the at least oneantifouling moiety is selected amongst fluorine (—F) and at least onegroup comprising a fluorine atom and said at least one surface-adsorbingmoiety being selected amongst dihydroxy-amino acids and dihydroxy-aminoacid containing groups, said at least one antifouling moiety and said atleast one surface-adsorbing moiety being associated to each other via acovalent bond or via a linker moiety. The film or coat may comprise atleast one antifouling moiety and at least one surface-adsorbing moiety,wherein the at least one antifouling moiety being selected amongstfluorine (—F) and at least one group comprising a fluorine atom and saidat least one surface-adsorbing moiety is selected amongst3,4-dihydroxy-L-phenylalanin (DOPA) and DOPA containing groups, andwherein said at least one antifouling moiety and said at least onesurface-adsorbing moiety being associated to each other via a covalentbond or via a linker moiety.

In some embodiments, said compound being of the general formula A-L-F,wherein A is a surface-adsorbing moiety, L is a covalent bond or alinker moiety linking A and F, and F is an antifouling moiety, andwherein each of A, L and F are associated to each other via anon-hydrolysable bond.

The film or coat is antifouling for preventing or arresting adsorptionof organic and/or bio-organic materials to said surface, or forpreventing or arresting adsorption of secretion products of cells ofmulti-cellular organisms or of microorganisms to a surface.

In some embodiments, the surface-adsorbing moiety is DOPA being linked,associated or bonded to an atom on said linker moiety. In someembodiments, said linker moiety is a one-carbon chain. In someembodiments, the linker moiety is selected from substituted orunsubstituted carbon chain. In some embodiments, the linker moiety isselected from amino acids and peptides. In some embodiments, the linkermoiety comprises between 1 to 40 carbon atoms. In some embodiments, thelinker moiety is substituted by one or more functional groups selectedfrom substituted or unsubstituted alkyl, substituted or unsubstitutedalkenyl, substituted or unsubstituted alkynyl, substituted orunsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl,substituted or unsubstituted cycloalkynyl, substituted or unsubstitutedaryl, substituted or unsubstituted heteroaryl, substituted orunsubstituted heterocyclyl, substituted or unsubstituted —NR₁R₂,substituted or unsubstituted —OR₃, substituted or unsubstituted —SR₄,substituted or unsubstituted—S(O)R₅, substituted or unsubstitutedalkylene-COOH, and substituted or unsubstituted ester.

In some embodiments, the linker moiety is of the general structure

-   -   wherein    -   each * denotes a point of connectivity;    -   n is between 0 and 40; and    -   m is between 1 and 40.

In some embodiments, n is between 1 and 12. In some embodiments, n isbetween 1 and 8. In some embodiments, n is between 1 and 6. In someembodiments, m is between 1 and 20. In some embodiments, m is between 1and 12. In some embodiments, m is between 1 and 8. In some embodiments,m is between 1 and 6.

In some embodiments, one or more of the (CH₂). groups are substituted.

In some embodiments, the linker moiety is an amino acid comprising 2 or3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or28 or 29 or 30 or 31 or 32 or 33 or 34 or 35 or 36 or 37 or 38 or 39 or40 amino acids.

In some embodiments, the compound is constructed of two amino acidsbonded to each other via an amide bond, wherein one amino acid is DOPAand the other being a fluorinated amino acid. In some embodiments, theantifouling moieties are bonded to the linker at one end and thesurface-adsorbing moieties at the other end of the linker moiety. Insome embodiments, the antifouling moieties and the surface-adsorbingmoieties are at alternating positions along the linker moiety.

In some embodiments, the linker moiety comprises or consists a peptideof two or more amino acids.

In some embodiments, the compound is a peptide having at least two aminoacids, at least one DOPA and at least fluorinated group, which may ormay not be a fluorinated amino acid. In some embodiments, the peptidecomprises between 2 and 40 amino acids. In some embodiments, the peptidecomprises 2, or 3, or 4, or 5, or 6, or 7, or 8 or 9 or 10 or 11 or 12amino acids.

In some embodiments, said antifouling moiety is a fluorinated amino acidselected amongst natural or unnatural amino acid, an amino acid analog,α- or β-forms, and L- or D amino acids. In some embodiments, the aminoacid is selected amongst alanine, arginine, asparagine, aspartic acid,cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine,leucine, lysine, methionine, phenylalanine, proline, serine, threonine,tryptophan, tyrosine valine, pyrrolysine and selnocysteine; and aminoacid analogs such as homo-amino acids, N-alkyl amino acids, dehydroaminoacids, aromatic amino acids and α,α-disubstituted amino acids, cystine,5-hydroxylysine, 4-hydroxyproline, a-aminoadipic acid, a-amino-n-butyricacid, 3,4-dihydroxyphenylalanine, homoserine, α-methylserine, ornithine,pipecolic acid, ortho, meta or para-aminobenzoic acid, citrulline,canavanine, norleucine, d-glutamic acid, aminobutyric acid,L-fluorenylalanine, L-3-benzothienylalanine and thyroxine.

In some embodiments, the amino acid is selected amongst aromatic aminoacids. In some embodiments, said aromatic amino acids are selected fromtryptophan, tyrosine, naphthyl alanine, and phenylalanine.

In some embodiments, the amino acids are selected from phenylalanine andderivatives thereof. In some embodiments, the phenylalanine derivativesare selected from 4-methoxy-phenylalanine, 4-carbamimidoyl-1-phenylalanine, 4-chloro-phenylalanine, 3-cyano-phenylalanine,4-bromo-phenylalanine, 4-cyano-phenylalanine,4-hydroxymethyl-phenylalanine, 4-methyl-phenylalanine,1-naphthyl-alanine, 3-(9-anthryl)-alanine, 3-methyl-phenylalanine,m-amidinophenyl-3-alanine, phenyl serine, benzylcysteine,4,4-biphenylalanine, 2-cyano-phenylalanine, 2,4-dichloro-phenylalanine,3,4-dichloro-phenylalanine, 2-chloro-penylalanine,3,4-dihydroxy-phenylalanine, 3,5-dibromotyrosine, 3,3-diphenylalanine,3-ethyl-phenylalanine, 3,4-difluoro-phenyl alanine,3-chloro-phenylalanine, 3-chloro-phenyl alanine, 2-fluoro-phenylalanine,3-fluoro-phenyl alanine, 4-amino-L-phenylalanine, homophenylal anine,3-(8-hydroxyquinolin-3-yl)-1-alanine, 3-iodo-tyrosine, kynurenine,3,4-dimethyl-phenylalanine, 2-methyl-phenylalanine, m-tyrosine,2-naphthyl-alanine, 5-hydroxy-1-naphthalene, 6-hydroxy-2-naphthalene,meta-nitro-tyrosine, (beta)-beta-hydroxy-1-tyrosine,(beta)-3-chloro-beta-hydroxy-1-tyrosine, o-tyrosine,4-benzoyl-phenylalanine, 3-(2-pyridyl)-alanine, 3-(3-pyridyl)-alanine,3-(4-pyridyl)-alanine, 3-(2-quinolyl)-alanine, 3-(3-quinolyl)-alanine,3-(4-quinolyl)-alanine, 3-(5-quinolyl)-alanine, 3-(6-quinolyl)-alanine,3-(2-quinoxalyl)-alanine, styryl alanine, pentafluoro-phenylalanine,4-fluoro-phenylalanine, phenyl alanine, 4-iodo-phenylalanine,4-nitro-phenylalanine, phosphotyrosine, 4-tert-butyl-phenylalanine,2-(trifluoromethyl)-phenylalanine, 3-(trifluoromethyl)-phenylalanine,4-(trifluoromethyl)-phenylalanine, 3-amino-L-tyrosine,3,5-diiodotyrosine, 3-amino-6-hydroxy-tyrosine, tyrosine,3,5-difluoro-phenylalanine and 3-fluorotyrosine.

In some embodiments, said fluorinated amino acidare selected fromo-fluorophenylalanine, m-fluorophenylalanine and p-fluorophenyl alanine.

In some embodiments, the compound comprising DOPA at one termini and afluorinated aromatic amino acid selected from o-fluorophenylalanine,m-fluorophenylalanine and p-fluorophenylalanine at the other termini.

In some embodiments, the compound comprising DOPA at a mid-point aminoacid along the peptide and a fluorinated aromatic amino acid selectedfrom o-fluorophenylalanine, m-fluorophenylalanine andp-fluorophenylalanine at each of the peptide termini.

In some embodiments, the film or coat is provided for preventing orarresting or minimizing or diminishing one or more of the following:

(b) adsorption of organic and/or bio-organic materials to a surface;

(b) adsorption of proteins and/or (poly)saccharides and (poly)lipids toa surface;

(c) secretion from cells of multi-organism or of micro-organisms onto asurface; and

(d) adsorption of cells of multi-organism or micro-organisms to asurface.

In some embodiments, the compound has the structure:

In some embodiments, the compound is selected fromNH₂-L-DOPA-L-(4-F)-Phe-COOH  Peptide 15NH₂-L-DOPA-D-(4-F)-Phe-COOH  Peptide 16NH₂-L-DOPA-L-(4-F)-Phe-L-(4-F)-Phe-COOMe  Peptide 17.

The invention also provides an article or a device comprising at leastone surface region coated with a film or coat according to theinvention. In some embodiments, the article or device is selected from amarine vessel, a hull of a marine vessel, a medical device, a contactlens, a food processing apparatus, a drinking water dispensingapparatus, a pipeline, a cable, a fishing net, a pillar of a bridge anda surface region of a water immersed article.

In some embodiments, the film or coat is provided for preventingbiofouling caused by an organism selected from bacteria, diatoms,hydroids, algae, bryozoans, protozoans, ascidians, tube worms, asiaticclams, zebra mussels and barnacles.

In some embodiments, the organisms are bacteria. In some embodiments,the bacteria are selected from Bordetella pertussis, Borreliaburgdorferi, Brucella abortus, Brucella canis, Brucella melitensis,Brucella suis, Campylobacter jejuni, Chlamydia pneumonia, Chlamydiapsittaci, Chlamydia trachomatis, Clostridium botulinum, Clostridiumdifficile, Clostridium perfringens, Clostridium tetani, Corynebacteriumdiphtheria, Enterococcus faecalis, Enterococcus faecium, Escherichiacoli (E. coli), Enterotoxigenic Escherichia coli (ETEC),Enteropathogenic E. coli, Francisella tularensis, Haemophilus influenza,Helicobacter pylori, Legionella pneumophila, Leptospira interrogans,Listeria monocytogenes, Mycobacterium leprae, Mycobacteriumtuberculosis, Mycoplasma pneumonia, Neisseria gonorrhoeae, Neisseriameningitidis, Pseudomonas aeruginosa, Rickettsia rickettsii, Salmonellatyphi, Salmonella typhimurium, Shigella sonnei, Staphylococcusepidermidis, Staphylococcus saprophyticus, Streptococcus agalactiae,Streptococcus mutans Streptococcus pneumonia, Streptococcus pyogenes,Treponema pallidum, Vibrio cholera, Vibrio harveyi and Yersinia pestis.

In some embodiments, the bacteria are Escherichia coli (E. Coli). Insome embodiments, the bacteria are P. aeruginosa.

The invention also provides a composition comprising a compound havingat least one antifouling moiety and at least one surface-adsorbingmoiety, wherein the at least one antifouling moiety is selected amongstfluorine (—F) and a group comprising at least one fluorine atom and saidat least one surface-adsorbing moiety being selected amongst3,4-dihydroxy-L-phenylalanin (DOPA) and DOPA containing groups, for usein forming a self-assembled antifouling film or coat on a surface regionof a device or an article.

The invention also a composition comprising a bifunctional compoundcomprising at least one antifouling moiety and at least onesurface-adsorbing moiety (or group), wherein the at least oneantifouling moiety is selected amongst fluorine (—F) and at least onegroup comprising a fluorine atom and said at least one surface-adsorbingmoiety being selected amongst dihydroxy-amino acids and dihydroxy-aminoacid containing groups, said at least one antifouling moiety and said atleast one surface-adsorbing moiety being associated to each other via acovalent bond or via a linker moiety.

In some embodiments, the composition comprises at least one antifoulingmoiety and at least one surface-adsorbing moiety, wherein the at leastone antifouling moiety being selected amongst fluorine (—F) and at leastone group comprising a fluorine atom and said at least onesurface-adsorbing moiety is selected amongst3,4-dihydroxy-L-phenylalanin (DOPA) and DOPA containing groups, andwherein said at least one antifouling moiety and said at least onesurface-adsorbing moiety being associated to each other via a covalentbond or via a linker moiety.

In some embodiments, the compound is of the general formula A-L-F,wherein A is a surface-adsorbing moiety, L is a covalent bond or alinker moiety linking A and F, and F is an antifouling moiety, andwherein each of A, L and F are associated to each other via anon-hydrolysable bond.

The composition is antifouling for preventing or arresting adsorption oforganic and/or bio-organic materials to said surface, or for preventingor arresting adsorption of secretion products of cells of multi-cellularorganisms or of microorganisms to a surface.

In some embodiments, the surface-adsorbing moiety is DOPA being linked,associated or bonded to an atom on said linker moiety. In someembodiments, said linker moiety is a one-carbon chain. In someembodiments, the linker moiety is selected from substituted orunsubstituted carbon chain. In some embodiments, the linker moiety isselected from amino acids and peptides. In some embodiments, the linkermoiety comprises between 1 to 40 carbon atoms. In some embodiments, thelinker moiety is substituted by one or more functional groups selectedfrom substituted or unsubstituted alkyl, substituted or unsubstitutedalkenyl, substituted or unsubstituted alkynyl, substituted orunsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl,substituted or unsubstituted cycloalkynyl, substituted or unsubstitutedaryl, substituted or unsubstituted heteroaryl, substituted orunsubstituted heterocyclyl, substituted or unsubstituted —NR₁R₂,substituted or unsubstituted —OR₃, substituted or unsubstituted —SR₄,substituted or unsubstituted—S(O)R₅, substituted or unsubstitutedalkylene-COOH, and substituted or unsubstituted ester.

In some embodiments, the linker moiety is of the general structure

-   -   wherein    -   each * denotes a point of connectivity;    -   n is between 0 and 40; and    -   m is between 1 and 40.

In some embodiments, n is between 1 and 12. In some embodiments, n isbetween 1 and 8. In some embodiments, n is between 1 and 6. In someembodiments, m is between 1 and 20. In some embodiments, m is between 1and 12. In some embodiments, m is between 1 and 8. In some embodiments,m is between 1 and 6.

In some embodiments, one or more of the (CH₂)_(n) groups aresubstituted.

In some embodiments, the linker moiety is an amino acid comprising 2 or3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or28 or 29 or 30 or 31 or 32 or 33 or 34 or 35 or 36 or 37 or 38 or 39 or40 amino acids.

In some embodiments, the compound is constructed of two amino acidsbonded to each other via an amide bond, wherein one amino acid is DOPAand the other being a fluorinated amino acid. In some embodiments, theantifouling moieties are bonded to the linker at one end and thesurface-adsorbing moieties at the other end of the linker moiety. Insome embodiments, the antifouling moieties and the surface-adsorbingmoieties are at alternating positions along the linker moiety.

In some embodiments, the linker moiety comprises or consists a peptideof two or more amino acids.

In some embodiments, the compound is a peptide having at least two aminoacids, at least one DOPA and at least fluorinated group, which may ormay not be a fluorinated amino acid. In some embodiments, the peptidecomprises between 2 and 40 amino acids. In some embodiments, the peptidecomprises 2, or 3, or 4, or 5, or 6, or 7, or 8 or 9 or 10 or 11 or 12amino acids.

In some embodiments, said antifouling moiety is a fluorinated amino acidselected amongst natural or unnatural amino acid, an amino acid analog,α- or β-forms, and L- or D amino acids. In some embodiments, the aminoacid is selected amongst alanine, arginine, asparagine, aspartic acid,cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine,leucine, lysine, methionine, phenylalanine, proline, serine, threonine,tryptophan, tyrosine valine, pyrrolysine and selnocysteine; and aminoacid analogs such as homo-amino acids, N-alkyl amino acids, dehydroaminoacids, aromatic amino acids and α,α-disubstituted amino acids, cystine,5-hydroxylysine, 4-hydroxyproline, a-aminoadipic acid, a-amino-n-butyricacid, 3,4-dihydroxyphenylalanine, homoserine, α-methylserine, ornithine,pipecolic acid, ortho, meta or para-aminobenzoic acid, citrulline,canavanine, norleucine, d-glutamic acid, aminobutyric acid,L-fluorenylalanine, L-3-benzothienylalanine and thyroxine.

In some embodiments, the amino acid is selected amongst aromatic aminoacids. In some embodiments, said aromatic amino acids are selected fromtryptophan, tyrosine, naphthylalanine, and phenylalanine.

In some embodiments, the amino acids are selected from phenylalanine andderivatives thereof. In some embodiments, the phenylalanine derivativesare selected from 4-methoxy-phenylalanine,4-carbamimidoyl-1-phenylalanine, 4-chloro-phenylalanine,3-cyano-phenylalanine, 4-bromo-phenylalanine, 4-cyano-phenylalanine,4-hydroxymethyl-phenylalanine, 4-methyl-phenylalanine,1-naphthyl-alanine, 3-(9-anthryl)-alanine, 3-methyl-phenylalanine,m-amidinophenyl-3-alanine, phenylserine, benzylcysteine,4,4-biphenylalanine, 2-cyano-phenylalanine, 2,4-dichloro-phenylalanine,3,4-dichloro-phenylalanine, 2-chloro-penylalanine,3,4-dihydroxy-phenylalanine, 3,5-dibromotyrosine, 3,3-diphenyl alanine,3-ethyl-phenylalanine, 3,4-difluoro-phenyl alanine,3-chloro-phenylalanine, 3-chloro-phenylalanine, 2-fluoro-phenylalanine,3-fluoro-phenylalanine, 4-amino-L-phenylalanine, homophenylalanine,3-(8-hydroxyquinolin-3-yl)-1-alanine, 3-iodo-tyrosine, kynurenine,3,4-dimethyl-phenylalanine, 2-methyl-phenylalanine, m-tyrosine,2-naphthyl-alanine, 5-hydroxy-1-naphthalene, 6-hydroxy-2-naphthalene,meta-nitro-tyrosine, (beta)-beta-hydroxy-1-tyrosine,(beta)-3-chloro-beta-hydroxy-1-tyrosine, o-tyrosine,4-benzoyl-phenylalanine, 3-(2-pyridyl)-alanine, 3-(3-pyridyl)-alanine,3-(4-pyridyl)-alanine, 3-(2-quinolyl)-alanine, 3-(3-quinolyl)-alanine,3-(4-quinolyl)-alanine, 3-(5-quinolyl)-alanine, 3-(6-quinolyl)-alanine,3-(2-quinoxalyl)-alanine, styrylalanine, pentafluoro-phenylalanine,4-fluoro-phenylalanine, phenylalanine, 4-iodo-phenylalanine,4-nitro-phenylalanine, phosphotyrosine, 4-tert-butyl-phenylalanine,2-(trifluoromethyl)-phenylalanine, 3-(trifluoromethyl)-phenylalanine,4-(trifluoromethyl)-phenylalanine, 3-amino-L-tyrosine,3,5-diiodotyrosine, 3-amino-6-hydroxy-tyrosine, tyrosine,3,5-difluoro-phenylalanine and 3-fluorotyrosine.

In some embodiments, said fluorinated amino acidare selected fromo-fluorophenylalanine, m-fluorophenylalanine and p-fluorophenylalanine.

In some embodiments, the compound comprising DOPA at one termini and afluorinated aromatic amino acid selected from o-fluorophenyl alanine,m-fluorophenylalanine and p-fluorophenylalanine at the other termini.

In some embodiments, the compound comprising DOPA at a mid-point aminoacid along the peptide and a fluorinated aromatic amino acid selectedfrom o-fluorophenylalanine, m-fluorophenylalanine andp-fluorophenylalanine at each of the peptide termini.

In some embodiments, the film or coat is provided for preventing orarresting or minimizing or diminishing one or more of the following:

(c) adsorption of organic and/or bio-organic materials to a surface;

(b) adsorption of proteins and/or (poly)saccharides and (poly)lipids toa surface;

(c) secretion from cells of multi-organism or of micro-organisms onto asurface; and

(d) adsorption of cells of multi-organism or micro-organisms to asurface.

In some embodiments, the compound has the structure:

In some embodiments, the compound is selected fromNH₂-L-DOPA-L-(4-F)-Phe-COOH  Peptide 15NH₁₂-L-DOPA-D-(4-F)-Phe-COOH  Peptide 16NH₂-L-DOPA-L-(4-F)-Phe-L-(4-F)-Phe-COOMe  Peptide 17.

In some embodiments, the composition is provided for preventingbiofouling caused by an organism selected from bacteria, diatoms,hydroids, algae, bryozoans, protozoans, ascidians, tube worms, asiaticclams, zebra mussels and barnacles.

In some embodiments, the organisms are bacteria. In some embodiments,the bacteria are selected from Bordetella pertussis, Borreliaburgdorferi, Brucella abortus, Brucella canis, Brucella melitensis,Brucella suis, Campylobacter jejuni, Chlamydia pneumonia, Chlamydiapsittaci, Chlamydia trachomatis, Clostridium botulinum, Clostridiumdifficile, Clostridium perfringens, Clostridium tetani, Corynebacteriumdiphtheria, Enterococcus faecalis, Enterococcus faecium, Escherichiacoli (E. coli), Enterotoxigenic Escherichia coli (ETEC),Enteropathogenic E. coli, Francisella tularensis, Haemophilus influenza,Helicobacter pylori, Legionella pneumophila, Leptospira interrogans,Listeria monocytogenes, Mycobacterium leprae, Mycobacteriumtuberculosis, Mycoplasma pneumonia, Neisseria gonorrhoeae, Neisseriameningitidis, Pseudomonas aeruginosa, Rickettsia rickettsii, Salmonellatyphi, Salmonella typhimurium, Shigella sonnei, Staphylococcusepidermidis, Staphylococcus saprophyticus, Streptococcus agalactiae,Streptococcus mutans Streptococcus pneumonia, Streptococcus pyogenes,Treponema pallidum, Vibrio cholera, Vibrio harveyi and Yersinia pestis.

In some embodiments, the bacteria are Escherichia coli (E. Coli). Insome embodiments, the bacteria are P. aeruginosa.

The invention further provides an antifouling formulation comprising acomposition according to the invention. Also provided is anantimicrobial formulation comprising a composition of the invention.Further provided is an antibacterial formulation comprising acomposition of the invention.

The invention further provides a kit comprising a composition accordingto the invention and instructions of use.

The invention also provides the use of a composition according to theinvention for making an antifouling formulation or antimicrobialformulation or antibacterial formulation.

The invention also provides a method for forming a film or a coat of aplurality of compounds on a surface region, the compounds eachcomprising at least one antifouling moiety and at least onesurface-adsorbing moiety, wherein the at least one antifouling moiety isselected amongst fluorine (—F) and a group comprising at least onefluorine atom and said at least one surface-adsorbing moiety beingselected amongst 3,4-dihydroxy-L-phenylalanin (DOPA) and DOPA containinggroups, the method comprising contacting said said surface region withsaid compounds and permitting self assembly thereof on said surfaceregion.

In some embodiments, said surface region is of a device or article. Insome embodiments, the compound is provided as a formulation. In someembodiments, said film or coat having a property selected fromantifouling, antimicrobial and antibacterial.

Materials and Methods

All chemicals, solvents, proteins and bacteria were purchased fromcommercially available companies and used as supplied unless otherwisestated. Fmoc-DOPA (ac)-COOH was obtained from Novabiochem/EMD chemicals(San-Diego, USA). L and D-4-fluoro phenylalanine, Boc-penta Fluorophe-COOH were purchased from chem-impex Inc. (Wood Dale, USA). Solventsand TFA were purchased from Bio-lab (Jerusalem, Israel). NMR solvents(CDCl₃ and DMSO-d₆) were supplied by Sigma-Aldrich (Jerusalem, Israel).Piperidine used for deprotection of Fmoc group was obtained fromAlfa-Aesar (UK). The proteins BSA, fibrinogen and lysozyme were obtainedfrom Sigma-Aldrich (Jerusalem, Israel), Chem impex INC. (Wood Dale, USA)and Merck (Darmstadt, Germany) respectively. Pseudomonas aeruginosa(ATCC 27853) and Eschrichia coli (ATCC 1655) were purchased from ATCC(Virginia, USA). Crystal violet was obtained from Merck (Germany).

Peptide Synthesis

NMR spectra were obtained at 400.13 MHz (¹H) using a Bruker DRX 400spectrometer. The mass of the peptides was measured using AppliedBiosystem Voyager-DE pro MALDI TOF mass spectrometer. The peptides weresynthesized by a conventional solution-phase method using a racemizationfree strategy. The Boc group and Fmoc group were used for N-terminalprotection and the C-terminus was protected as a methyl ester. Couplingswere mediated by di cyclohexylcarbodiimide/1-hydroxybenzotriazole(DCC/HOBt). The intermediate compounds were characterized by ¹H NMR andMALDI-TOF mass spectroscopy and final peptides were fully characterizedby ¹H NMR, ¹³C NMR, ¹⁹F NMR, MALDI-TOF.

A. Synthesis of Peptide 1

1. Boc-L-(4F)Phe-COOH 7a:

A solution of L-4F-Phe-COOH 1.97 g (10 mmol) in a mixture of dioxane (20mL), water (20 mL) and 1 M NaOH (10 mL) was stirred and cooled in anice-water bath. Ditert-butylpyrocarbonate 2.4 g (11 mmol) was added andstirring was continued at room temperature for 6 h. Then the solutionwas concentrated in vacuum to about 15-20 mL, cooled in an ice waterbath, covered with a layer of ethyl acetate (about 30 mL) and a dilutesolution of KHSO₄ was added to acidify (pH 2-3). The aqueous phase wasextracted with ethyl acetate and this operation was done three times.The ethyl acetate extracts were collected and dried over anhydrousNa₂SO₄ and evaporated in a vacuum. The pure material was obtained as awaxy solid.

Yield: 2.115 g (7.25 mmol, 72.5%)

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 12.60 [s, 1H COOH], 7.29-7.25 &7.11-7.07 [m, 4H, Aromatic protons], 4.10-3.00 [m, 1H, CαH 4F Phe],3.03-2.77 [m, 2H, CβH 4F Phe], 1.33 [s, 9H, Boc].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+H]+284.12 (calculated), 284.29 (observed), [M+Na]+ 306.11 (calculated),306.25 (observed).

2. Boc-L-(4F)Phe(2)-L-(4F)Phe(3)-COOMe 8a:

500 mg (1.766 mmol) of Boc-L-(4F)Phe-OH was dissolved in 25 mL dry DCMin an ice-water bath. NH₂-L-(4F)Phe-OMe 697.13 mg (3.532 mmol) wasisolated from the corresponding methyl ester hydrochloride byneutralization, subsequent extraction with ethyl acetate and solventevaporation. It was then added to the reaction mixture, followedimmediately by 365 mg (1.766 mmol) dicyclohexylcarbodiimide (DCC) and239 mg (1.766 mmol) of HOBt. The reaction mixture was allowed to come toroom temperature and stirred for 48 h. DCM was evaporated and theresidue was dissolved in ethyl acetate (60 mL) and dicyclohexyl urea(DCU) was filtered off. The organic layer was washed with 2 M HCl (3×30mL), brine (2×30 mL), 1 M sodium carbonate (3×30 mL) and brine (2×30 mL)and dried over anhydrous sodium sulfate; and evaporated in a vacuum toyield compound 8a, as a white solid. The product was purified by silicagel (100-200 mesh) using n hexane-ethyl acetate (4:1) as eluent.

Yield: 616.6 mg (1.334 mmol, 75.5%)

¹H NMR (CDCl₃, 400 MHz, δ_(ppm)): 7.16-7.12 & 6.99-6.90 [m, 8H, Aromaticprotons], 6.27-6.25 [d, 1H, NH 4F Phe(3)], 4.93 [b, 1H, NH 4F Phe(2)],4.77-4.72 [m, 1H, CαH 4F Phe(3)], 4.28-4.27 [m, 1H, CαH 4F Phe(2)], 3.67[s, 3H, OMe], 3.08-2.98 [m, 4H, CβH 4F Phe(2) and 4F Phe(3)], 1.41 [s,9H, Boc].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na]⁺485.18 (calculated), 485.45 (observed), [M+K]⁺ 501.16 (calculated),501.32 (observed).

3. NH₂-L-(4F)Phe(2)-L-(4F)Phe(3)-COOMe 9a:

600 mg (1.298 mmol) compound 8a was dissolved in 16 mL of DCM in an icebath. Then 4 ml of TFA was added and stirred for 2 h. The progress ofreaction was monitored through TLC (Thin layer chromatography). Aftercompletion of reaction all the solvents were evaporated in rotaryevaporator. The product was dissolved in water, neutralized with NaHCO₃solution and extracted with ethyl acetate, dried over anhydrous sodiumsulphate, evaporated into rotary evaporator to get oily product 9a.

Yield: 435.3 mg (1.202 mmol, 92.6%)

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 9.06-9.05 [d, 1H, NH 4F Phe(3)],7.32-7.26 & 7.17-7.04 [m, 8H, Aromatic protons], 4.57-4.51 [m, 1H, CαH4F Phe(3)], 4.04-3.96 [m, 1H, CαH 4F Phe(2)], 3.61 [s, 3H, OMe],3.18-2.91 [m, 4H, CβH 4F Phe(2) and 4F Phe(3)].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+2H]⁺364.14 (calculated), 364.34 (observed), [M+H₂O]⁻ 480.15 (calculated),480.35 (observed).

4. Fmoc-L-DOPA(ac)-L-(4F)Phe(2)-L-(4F)Phe(3)-COOMe 10a:

430 mg (1.187 mmol) of compound 9a was dissolved in 25 mL dry DCM in anice-water bath and 652.37 mg (1.42 mmol) of Fmoc-L-DOPA(ac)-COOH wasadded. Then 245 mg (1.187 mmol) dicyclohexylcarbodiimide (DCC) and 161mg (1.187 mmol) of HOBt were added to reaction mixture. The reactionmixture was allowed to come to room temperature and stirred for 48 h.DCM was evaporated and the residue was dissolved in ethyl acetate (60mL) and dicyclohexylurea (DCU) was filtered off. The organic layer waswashed with water, extracted, dried over anhydrous sodium sulfate andevaporated in a vacuum to yield compound 10a, as a white solid. Theproduct was purified by silica gel (100-200 mesh) using n hexane-ethylacetate (4:1) as eluent.

Yield: 594.8 mg (0.74 mmol, 62.4%).

¹H NMR (CDCl₃, 400 MHz, δ_(ppm)): 7.77-7.75, 7.54-7.50, 7.42-7.38,7.33-7.29 [d & m, 8H, Fmoc aromatic protons], 7.05-6.86 [m, 8H, 4FPhe(2) and 4F Phe(3) aromatic protons], 6.62-6.55 [s & m, 3H, DOPAaromatic protons], 6.50 [b, 1H, NH 4F Phe(2)], 6.19 [b, 1H, NH 4FPhe(3)], 5.17 [b, 1H, NH DOPA], 4.68-4.66 [m, 1H, CαH DOPA], 4.54-4.52[m, 1H, CαH 4F Phe(2)], 4.47-4.42 [m, 1H, CαH 4F Phe(3)], 4.31 (b, 2H,CβH Fmoc], 4.20-4.17 [m, 1H, CαH Fmoc], 3.65 [s, 3H, OMe], 2.98-2.92 [m,6H, CβH 4F Phe(2) 4F Phe(3) & DOPA], 1.62 [s, 6H, 2×COCH₃].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+H]⁺804.31 (calculated), 804.70 (observed), [M+Na+2H]⁻ 828.30 (calculated),828.07 (observed), [M+K+H]⁻ 843.27 (calculated), 843.60 (observed).

5. NH₂-L-DOPA(ac)-L-(4F)Phe(2)-L-(4F)Phe(3)-COOMe 11a:

580 mg (0.721 mmol) of compound 10a was treated 15 mL with 20%Piperidine solution and stirred for 3h in room temperature. Thecompletion of reaction was monitored by TLC. Then the solution waslyophilized and purified with column chromatography to get pure stickycompound 11a.

Yield: 275.6 mg (0.474 mmol, 65.8%)

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 8.53 [b, 1H, NH 4F Phe(2)], 7.96 [b,1H, NH 4F Phe(3)], 7.24-7.23, 7.10-7.04 [m, 8H, 4F Phe(2) and 4F Phe(3)aromatic protons], 6.69-6.65, 6.55-6.53 [m, 3H, DOPA aromatic protons],5.56 [m, 1H, CαH DOPA], 4.56 [m, 1H, CαH 4F Phe(2)], 4.47 [m, 1H, 4FPhe(3)], 3.61 [s, 3H, OMe], 3.12-2.73 [m, 6H, CβH 4F Phe(2) 4F Phe(3) &DOPA], 1.61-1.58 [d, 6H, 2×COCH₃].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+H]⁺582.23 (calculated), 582.25 (observed), [M+Na]⁺ 604.22 (calculated),604.37 (observed), [M+K]⁺ 620.20 (calculated), 620.19 (observed).

6. NH₂-L-DOPA-L(4F)-Phe(2)-L(4F)-Phe(3)-COOMe 1:

260 mg (0.447 mmol) of compound 11a, was stirred in 10 mL of 95% TFA inwater for 6 h. The progress of the reaction was monitored through TLC.After completion of reaction the solvent was evaporated in rotaryevaporator. The product was washed with hexane, cold ether and waterthree times each to get final peptide 1.

Yield: 139.1 mg (0.257 mmol, 57.5%)

¹H NMR (DMSO-d₆, 500 MHz, δ_(ppm)): 8.72-8.70 [d, 1H, NH 4F Phe(2)],8.66-8.64 [d, 1H, NH 4F Phe(3)], 7.88 [b, 2H, OH DOPA], 7.29-7.23,7.12-7.05 [m, 8H, 4F Phe(2) and 4F Phe(3) aromatic protons], 6.7-6.64,6.5-6.47 [m, 3H, DOPA aromatic protons], 4.60-4.58 [m, 1H, CαH 4FPhe(2)], 4.53-4.52 [m, 1H, CαH 4F Phe(3)], 3.83 [m, 1H, CαH DOPA], 3.58[s, 3H, OMe], 3.08-2.75 [m, 6H, CβH 4F Phe(2) 4F Phe(3) & DOPA]. ¹³C NMR(DMSO-d₆, 125 MHz, δ_(ppm)): 171.9, 170.1, 168.5, 158.9, 158.54, 145.2,144.5, 131.5, 125.2, 117.4, 115.5, 115.4, 115.3, 11.2, 114.5, 53.9,52.3, 47.5, 36.2, 33.8, 25.8, 24.9. ¹⁹F NMR (DMSO-d6, 470 MHz, δ_(ppm)):−116.42, −116.71.

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+H]⁺542.20 (calculated), 542.57 (observed), [M+Na]⁺ 564.19 (calculated),564.46 (observed), [M+K]⁺ 580.16 (calculated), 580.32 (observed).

B. Synthesis of Peptide 2

1. Boc-L-(4F)Phe(2)-D-(4F)Phe(3)-COOMe 8b:

The compound was synthesized with the same procedure as compound 8a.

¹H NMR (CDCl₃, 400 MHz, δ_(ppm)): 7.13-7.10 & 6.98-6.91 [m, 8H, Aromaticprotons], 6.51 [b, 1H, NH 4F Phe(3)], 4.91-4.89 [d, 1H, NH 4F Phe(2)],4.82-4.77 [m, 1H, CαH 4F Phe(3)], 4.33 [m, 1H, CαH 4F Phe(1)], 3.68 [s,3H, OMe], 3.09-2.93 [m, 4H, CβH 4F Phe(2) and 4F Phe(3)], 1.38 [s, 9H,Boc].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+2H]⁺464.21 (calculated), 464.15 (observed), [M+Na+2H]⁺ 586.18 (calculated),586.37, [M+K+H]⁺ 502.16 (calculated), 502.25 (observed).

2. NH₂-L-(4F)Phe(2)-D-(4F)Phe(3)-COOMe 9b:

The compound was synthesized with the same procedure as compound 9a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 8.34 [d, 1H, NH 4F Phe(3)],7.23-7.19 & 7.12-7.01 [m, 8H, Aromatic protons], 4.61-4.51 [m, 1H, CαH4F Phe(3)], 3.62 [s, 3H, OMe], 3.44-3.41 [m, 1H, CαH 4F Phe(2)],3.03-2.74 [m, 4H, CβH 4F Phe(2) and 4F Phe(3)]. 2.35 (b, 2H, free NH₂].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+2H]⁺364.14 (calculated), 364.41 (observed).

3. Fmoc-L-DOPA(ac)-L-(4F)Phe(2)-D-(4F)Phe(3)-COOMe 10b:

The compound was synthesized with the same procedure as compound 10a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 8.68-8.55 [d, 1H, NH Phe(2)],8.15-7.92 [d, 1H, NH 4F Phe(3)], 7.88-7.86, 7.61-6.96 [d & m, 16H, Fmocaromatic protons, 4F Phe(2) and 4F Phe(3) aromatic protons], 6.75 & 6.64[s, 3H, DOPA aromatic protons], 5.83 [d, 1H, NH DOPA], 4.62-4.53 [m, 2H,CαH 4F Phe(2) and Phe(3)], 4.14-4.02 [m, 3H, CαH DOPA & CβH Fmoc], 3.63[s, 3H, OMe], 2.76-2.57 [m, 6H, CβH 4F Phe(2), 4F Phe(3) & DOPA], 1.55[s, 6H, 2×COCH₃].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na]⁺826.29 (calculated), 826.15 (observed), [M+K]⁺ 842.27 (calculated),841.94 (observed).

4. NH₂-L-DOPA(ac)-L-(4F)Phe(2)-D-(4F)Phe(3)-COOMe 11b:

The compound was synthesized with the same procedure as compound 11a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 8.66-8.64 [b, 1H, NH 4F Phe(2)],7.95 [b, 1H, NH 4F Phe(3)], 7.30-6.80 [m, 8H, 4F Phe(2) and 4F Phe(3)aromatic protons], 6.68-6.64, 6.56-6.53 [m, 3H, DOPA aromatic protons],5.57-5.55 [m, 1H, CαH DOPA], 4.56 [m, 1H, CαH 4F Phe(2)], 4.47 [m, 1H,4F Phe(3)], 3.63 [s, 3H, OMe], 3.05-2.67 [m, 6H, CβH 4F Phe(2), 4FPhe(3) & DOPA]. 1.59-1.57 [s, 6H, 2×COCH₃].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na]⁺604.22 (calculated), 604.06 (observed), [M+K]⁺ 620.20 (calculated),619.88 (observed).

5. NH₂-L-DOPA-L-(4F)Phe(2)-D-(4F)Phe(3)-COOMe 2:

The peptide 2 was synthesized with the same procedure as peptide 1.

¹H NMR (DMSO-d₆, 500 MHz, δ_(ppm)): 8.77-8.75 [d, 1H, NH 4F Phe(2)],8.66-8.64 [d, 1H, NH 4F Phe(3)], 7.80 [b, 2H, OH DOPA], 7.27-7.24,7.11-7.00 [m, 8H, 4F Phe(2) and 4F Phe(3) aromatic protons], 6.71-6.60[m, 3H, DOPA aromatic protons], 5.15 [b, 2H, NH2], 4.62-4.60 [m, 1H, CαH4F Phe(2)], 4.52-4.49 [m, 1H, CαH 4F Phe(3)], 3.83 [m, 1H, CαH DOPA],3.65 [s, 3H, OMe], 3.10-2.73 [m, 6H, CβH 4F Phe(2), 4F Phe(3) & DOPA].¹³C NMR (DMSO-d₆, 125 MHz, δ_(ppm)): 117.43, 170.42, 147.86, 146.63,143.75, 143.69, 141.30, 135.47, 128.64, 127.75, 127.23, 127.13, 125.054,121.81, 120.02, 118.04, 109.44, 108.25, 67.20, 53.02, 52.33, 47.09,37.91, 31.94, 29.71, 25.89.

¹⁹F NMR (DMSO-d₆, 470 MHz, δ_(ppm)): −116.43,-116.91.

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+H]⁺542.20 (calculated), 542.65 (observed), [M+Na]⁺ 564.19 (calculated),564.55 (observed), [M+K]⁺ 580.16 (calculated), 580.57 (observed).

C. Synthesis of Peptide 3

1. Boc-D-(4F)Phe-COOH 7b:

The compound 7b was synthesized as compound 7a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 12.59 [s, 1H COOH], 7.29-7.26 &7.12-7.08 [m, 4H, Aromatic protons], 4.10-3.57 [m, 1H, CαH 4F Phe],3.03-2.77 [m, 2H, CβH 4F Phe], 1.32 [s, 9H, Boc].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+H]⁺284.12 (calculated), 284.36 (observed), [M+Na]⁺ 306.11 (calculated),306.28 (observed).

2. Boc-D-(4F)Phe(2)-L-(4F)Phe(3)-COOMe 8c:

The compound was synthesized with the same procedure as compound 8a.

¹H NMR (CDCl₃, 400 MHz, δ_(ppm)): 7.14-7.09 & 6.99-6.93 [m, 8H, Aromaticprotons], 6.50 [b, 1H, NH 4F Phe(3)], 4.88 [b, 1H, NH 4F Phe(2)],4.82-4.77 [m, 1H, CαH 4F Phe(3)], 4.33 [m, 1H, CαH 4F Phe(2)], 3.68 [s,3H, OMe], 3.09-2.91 [m, 4H, CβH 4F Phe(2) and 4F Phe(3)], 1.38 [s, 9H,Boc].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na]⁺485.18 (calculated), 485.88 (observed), [M+K]⁺ 501.16 (calculated),501.75 (observed).

3. NH₂-D-(4F)Phe(2)-L-(4F)Phe(3)-COOMe 9c:

The compound was synthesized with the same procedure as compound 9a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 8.71-8.67 [d, 1H, NH 4F Phe(3)],7.25-7.21 & 7.12-7.03 [m, 8H, Aromatic protons], 5.49 [b, 2H, NH₂],4.56-4.54 [m, 1H, CαH 4F Phe(2)], 3.77-3.70[m, 1H, CαH 4F Phe(3)], 3.64[s, 3H, OMe] 3.07-2.57 [m, 4H, CβH 4F Phe(2) and 4F Phe(3)].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+2H]⁺364.14 (calculated), 364.26 (observed).

4. Fmoc-L-DOPA(ac)-D-(4F)Phe(2)-L-(4F)Phe(3)-COOMe 10c:

The compound was synthesized with the same procedure as compound 10a.

¹H NMR (CDCl₃, 400 MHz, δ_(ppm)): 7.79-7.72, 7.51-7.47, 7.42-7.38,7.33-7.29 [d & m, 8H, Fmoc aromatic protons], 6.94-6.88 [m, 8H, 4FPhe(2) and 4F Phe(3) aromatic protons], 6.76-6.61[s & m, 3H, DOPAaromatic protons], 6.54 [b, 1H, NH 4F Phe(2)], 6.18 [b, 1H, NH 4FPhe(3)], 5.20 [b, 1H, NH DOPA], 4.76-4.68 [m, 1H, CαH DOPA], 4.67-4.57[m, 1H, CαH 4F Phe(2)], 4.43-4.35 [m, 1H, CαH 4F Phe(3)],], 4.30-4.21[m, 1H, CαH Fmoc], 4.19-4.01 (b, 2H, CβH Fmoc], 3.62 [s, 3H, OMe],3.09-2.75 [m, 6H, CβH 4F Phe(2), 4F Phe(3) & DOPA], 1.63 [s, 6H,2×COCH₃].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+H]⁺804.31 (calculated), 804.74 (observed), [M+Na+H]⁺ 827.30 (calculated),827.32 (observed), [M+K+H]⁺ 843.27 (calculated), 843.62 (observed).

5. NH₂-L-DOPA(ac)-D-(4F)Phe(2)-L-(4F)Phe(3)-COOMe 11c:

The compound was synthesized with the same procedure as compound 11a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 8.66-8.64 [b, 1H, NH 4F Phe(2)],7.95 [b, 1H, NH 4F Phe(3)], 7.29-6.81 [m, 8H, 4F Phe(2) and 4F Phe(3)aromatic protons], 6.68-6.64, 6.54-6.53 [m, 3H, DOPA aromatic protons],5.57-5.55 [m, 1H, CαH DOPA], 4.60 [m, 1H, CαH 4F Phe(2)], 4.48 [m, 1H,4F Phe(3)], 3.63 [s, 3H, OMe], 2.88-2.73 [m, 6H, CβH 4F Phe(2), 4FPhe(3) & DOPA]. 1.59-1.56 [s, 6H, 2×COCH₃].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+H]⁺582.23 (calculated), 581.93 (observed), [M+Na]⁺ 604.22 (calculated),604.01 (observed), [M+K]⁺ 620.20 (calculated), 619.85 (observed).

6. NH₂-L-DOPA-D-(4F)Phe(2)-L-(4F)Phe(3)-COOMe 3:

The peptide 3 was synthesized with the same procedure as peptide 1.

¹H NMR (DMSO-d₆, 500 MHz, δ_(ppm)): 8.72-8.71 [d, 1H, NH 4F Phe(2)],8.65-8.64 [d, 1H, NH 4F Phe(3)], 7.89 [b, 2H, OH DOPA], 7.28-7.23,7.12-7.06 [m, 8H, 4F Phe(2) and 4F Phe(3) aromatic protons], 6.67-6.64,6.49-6.47 [m, 3H, DOPA aromatic protons], 4.61-4.50 [m, 1H, CαH 4FPhe(2)& Phe(3)], 3.85-3.80 [m, 1H, CαH DOPA], 3.58 [s, 3H, OMe],3.05-2.72 [m, 6H, CβH 4F Phe(2), 4F Phe(3) & DOPA]. ¹³C NMR (DMSO-d₆,125 MHz, δ_(ppm)): 171.9, 170.9, 168.6, 162.5, 160.6, 158.5, 158.23,145.7, 145.1, 133.8, 133.7, 133.5, 131.5, 125.8, 120.7, 117.3, 116.1,115.5, 115.4, 115.3, 115.2, 54.3, 53.9, 52.4, 46.2, 37.3, 37.0, 36.2,26.7, 25.3, 24.7.

¹⁹F NMR (DMSO-d₆, 470 MHz, δ_(ppm)): −116.31, −116.53.

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+H]⁺542.20 (calculated), 542.51 (observed), [M+Na]⁺ 564.19 (calculated),564.53 (observed), [M+K]⁺ 580.16 (calculated), 580.43 (observed).

D. Synthesis of Peptide 4

1. Boc-D-(4F)Phe(2)-D-(4F)Phe(3)-COOMe 8d:

The compound was synthesized with the same procedure as compound 8a.

¹H NMR (CDCl₃, 400 MHz, δ_(ppm)): 7.18-7.15 & 7.01-6.925 [m, 8H,Aromatic protons], 6.25-6.23 [d, 1H, NH 4F Phe(3)], 4.93 [b, 1H, NH 4FPhe(2)], 4.77-4.76 [m, 1H, CαH 4F Phe(2)], 4.30-4.28 [m, 1H, CαH 4FPhe(3)], 3.7 [s, 3H, OMe], 3.10-3.00 [m, 4H, CβH 4F Phe(2) and 4FPhe(3)], 1.40 [s, 9H, Boc].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na+H]⁺486.18 (calculated), 485.93 (observed), [M+K+H]⁺ 502.16 (calculated),502.00 (observed).

2. NH₂-D-(4F)Phe(2)-D-(4F)Phe(3)-COOMe 9d:

The compound was synthesized with the same procedure as compound 9a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 8.36-8.34 [d, 1H, NH 4F Phe(3)],8.02 [b, 1H, NH 4F Phe(2)], 7.22-7.17 & 7.11-7.01 [m, 8H, aromaticprotons], 4.55-4.50 [m, 1H, CαH 4F Phe(3)], 4.08-3.92 [m, 1H, CαH 4FPhe(2)], 3.60 [s, 3H, OMe], 3.04-2.84 [m, 4H, CβH 4F Phe(2) and 4FPhe(3)].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+2H]⁺364.14 (calculated), 364.29 (observed), [M+Na+H]⁺ 486.13 (calculated),486.33 (observed).

3. Fmoc-L-DOPA(ac)-D-(4F)Phe(2)-D-(4F)Phe(3)-COOMe 10d:

The compound was synthesized with the same procedure as compound 10a.

¹H NMR (CDCl₃, 400 MHz, δ_(ppm)): 7.77-7.75, 7.55-7.53, 7.42-7.40 [d &m, 8H, Fmoc aromatic protons], 6.94-6.55 [m, 8H, 4F Phe(2) and 4F Phe(3)aromatic protons], 6.71-6.52 [m, 3H, DOPA aromatic protons], 6.52-6.45[b, 1H, NH 4F Phe(2)], 6.15 [b, 1H, NH 4F Phe(3)], 5.31 [b, 1H, NHDOPA], 4.73-4.65 [m, 1H, CαH DOPA], 4.64-4.56 [m, CαH 4F Phe(2)],4.51-4.42 [m, 1H, CαH 4F Phe(3)], 4.24-4.11 [m, 1H, CαH Fmoc], 4.19 (b,2H, CβH Fmoc], 3.61 [s, 3H, OMe], 3.08-2.72 [m, 6H, CβH 4F Phe(2) 4FPhe(3) & DOPA], 1.62 [s, 6H, 2×COCH₃].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)):m/z=[M+Na+2H]⁺ 828.30 (calculated), 828.03 (observed), [M+K+2H]⁺ 844.27(calculated), 844.12 (observed).

4. NH₂-L-DOPA(ac)-D-(4F)-Phe(2)-D-(4F)-Phe(3)-COOMe 11d:

The compound was synthesized with the same procedure as compound 11a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 8.58-8.53 [d, 1H, NH 4F Phe(2)],8.12 [d, 1H, NH 4F Phe(3)], 7.31-7.09 [m, 8H, 4F Phe(2) and 4F Phe(3)aromatic protons], 6.69-6.68, 6.61-6.60 [m, 3H, DOPA aromatic protons],5.63-5.61 [m, 1H, CαH DOPA], 4.61 [m, 1H, CαH 4F Phe(2)], 4.52 [m, 1H,4F Phe(3)], 3.64 [s, 3H, OMe], 3.15-2.65 [m, 6H, CβH 4F Phe(2) 4F Phe(3)& DOPA]. 1.54 [ d, 6H, 2×COCH₃].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na]⁺604.22 (calculated), 604.23 (observed), [M+K]⁺ 620.20 (calculated),620.12 (observed).

5. NH₂-L-DOPA-D-(4F)Phe(2)-D-(4F)Phe(3)-COOMe 4:

The peptide 4 was synthesized with the same procedure as peptide 1.

¹H NMR (DMSO-d₆, 500 MHz, δ_(ppm)): 8.80-8.77 [d, 1H, NH 4F Phe(2)],7.95 [b, 2H, OH DOPA], 7.31-7.20, 7.12-7.03 [m, 8H, 4F Phe(2) and 4FPhe(3) aromatic protons], 6.59-6.57, 6.22-6.20 [m, 3H, DOPA aromaticprotons], 5.58 [b, 2H, free NH2)], 4.75-4.62 [m, 1H, CαH 4F Phe(2)],4.51-4.45 [m, 1H, CαH 4F Phe(3)], 3.91-3.82 [m, 1H, CαH DOPA], 3.62 [s,3H, OMe], 3.08-2.62 [m, 6H, CβH 4F Phe(2), 4F Phe(3) & DOPA]. ¹³C NMR(DMSO-d₆, 125 MHz, δ_(ppm)): 172.01, 171.20, 168.27, 162.77, 158.59,158.27, 157.09, 145.65, 145.02, 133.58, 133.71, 131.46, 131.45, 131.37,125.74, 120.65, 117.37, 115.95, 115.63, 115.42, 115.31, 115.09, 54.14,52.44, 47.97, 33.80, 25.78, 24.92. ¹⁹F NMR (DMSO-d6, 470 MHz, δ_(ppm)):−116.08, −116.42.

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+H]⁺542.20 (calculated), 542.85 (observed), [M+Na]⁺ 564.19 (calculated),564.55 (observed), [M+K]⁺ 580.16 (calculated), 580.40 (observed).

E. Synthesis of Peptide 5

1. Boc-L-(F5)Phe(2)-L-(F5)Phe(3)-COOMe 8e.

We have purchased Boc-L-(F5)Phe-COOH. We first deprotected the Boc groupby treatment of TFA/DCM, then evaporate all the solvents andesterification of NH₂-Phe(F5)-COOH was done by treating with thionylchloride and methanol. Then the compound 8e was synthesized by couplingof Boc-L-(F5)Phe-COOH with NH₂-L-(F5)Phe-COOMe as described for compound8a.

¹H NMR (CDCl₃, 400 MHz, δ_(ppm)): 6.52 [b, 1H, NH Phe(3)], 4.93 [b, 1H,NH 4F Phe(2)], 4.92-4.85 [m, 1H, CαH Phe(3)], 4.42-4.29 [m, 1H, CαHPhe(2)], 3.81 [s, 3H, OMe], 3.42-2.95 [m, 4H, CβH Phe(2) and Phe(3)],1.44 [s, 9H, Boc].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na+H]⁺630.11 (calculated), 630.08 (observed), [M+K+H]⁻ 646.08 (calculated),646.13 (observed).

2. NH₂-L-(F5)Phe(2)-L-(F5)Phe(3)-COOMe 9e.

The compound 9e was prepared as described for compound 9a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 8.93-8.90 [d, 1H, NH Phe(3)], 8.40[b, 1H, free NH₂], 4.72-4.70 [m, 1H, CαH Phe(3)], 3.90 [m, 1H, CαHPhe(2)], 3.61 [s, 3H, OMe], 3.17-2.99 [m, 4H, CβH Phe(2) and Phe(3)].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na+H]⁺530.05 (calculated), 530.16 (observed), [M+K+H]⁻ 546.03 (calculated),646.53 (observed).

3. Fmoc-DOPA(ac)-L-(F5)Phe(2)-L-(F5)Phe(3)-COOMe 10e.

The compound 10e was prepared as described for compound 10a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 8.75-8.72 [d, 1H, NH Phe(2)],8.36-8.34 [b, 1H, NH Phe(3)], 7.88-7.26 [m, 8H, Fmoc aromatic protons],6.79-6.67 [m, 3H, DOPA aromatic protons], 5.57-5.55 [b, 1H, NH DOPA],4.66-4.63 [m, 2H, CβH Fmoc], 4.14-4.09 [m, 3H, CαH DOPA, CαH Phe(2), CαHPhe(3)], 3.62 [s, 3H, OMe], 3.05-2.90 [m, 6H, CβH Phe(2), Phe(3) &DOPA], 1.56 [s, 6H, 2×COCH₃].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na]⁺970.21 (calculated), 970.22 (observed), [M+K]⁺ 986.19 (calculated),986.04 (observed).

4. NH₂-DOPA(ac)-L-(F5)Phe(2)-L-(F5)Phe(3)-COOMe 11e

The compound 11e was prepared as described for compound 11a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 8.73-8.71 [d, 1H, NH Phe(2)],6.69-6.55 [m, 3H, DOPA aromatic protons], 5.57-5.55 [d, 1H, NH Phe(3)],4.64-6.63 [m, 1H, CαH DOPA], 4.54 [m, 1H, CαH Phe(2)], 4.13-4.08 [m, 1H,CαH Phe(3)], 3.61 [s, 3H, OMe], 3.15-2.67 [m, 6H, CβH Phe(2), Phe(3) &DOPA], 1.60 [s, 6H, 2×COCH₃].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na]⁺748.15 (calculated), 748.23 (observed), [M+K]⁺ 764.12 (calculated),764.06 (observed).

5. NH₂-DOPA-L-(F5)Phe(2)-L-(F5)Phe(3)-COOMe 5

The compound 5 was prepared as described for compound 1.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 9.46 [b, 1H, NH Phe(2)], 9.25 [b,1H, NH Phe(2)], 8.39 [b, 2H, free NH₂), 6.68-6.54 [m, 3H, DOPA aromaticprotons], 4.69-4.65 [m, 2H, CαH Phe (1) & Phe(2)], 4.55 [m, 1H, CαHDOPA], 3.61 [s, 3H, OMe], 3.01-2.95 67 [m, 6H, CβH Phe(2) Phe(2) &DOPA]. ¹³C NMR (DMSO-d₆, 100 MHz, δ_(ppm)): 193.6, 158.5, 158.2, 144.3,140.8, 139.5, 133.7, 129.9, 128.5, 127.8, 124.4, 53.8, 44.2, 33.8, 30.5,29.4, 22.6, 17.6. ¹⁹F (DMSO-d₆, 470 MHz, δ_(ppm)): −141.7, −142.4,−157.6, −163.1, −163.4.

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na]⁺748.15 (calculated), 748.23 (observed), [M+K]⁺ 764.12 (calculated),764.06 (observed).

F. Synthesis of peptide 6

1. Boc-L-DOPA-COOH:

The compound was synthesized as compound 7a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 9.13 (b, 2H, 2×OH], 7.35-7.33 [d,1H, NH DOPA], 7.03-6.88[m, 3H, DOPA aromatic protons], 4.45-4.37 [m, 1H,CαH DOPA], 3.22-2.92 [m, 1H, CβH DOPA], 1.75 [s, 9H, OMe].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na]⁺320.11 (calculated), 320.51 (observed), [M+K]⁻ 336.08 (calculated),336.29 (observed).

2. Boc-L-DOPA-L-(4F) Phe-COOMe:

The compound was synthesized as compound 8a.

¹H NMR (CDCl₃, 400 MHz, δ_(ppm)): 7.26-7.24 [d, 1H, NH Phe], 6.90-6.50[m, 7H, all aromatic protons], 5.24 [b, 1H, NH DOPA], 4.82-4.77 [m, 1H,CαH DOPA], 4.36 [b, 1H, CαH Phe], 3.64 [s, 3H, OMe], 2.99-2.87 [m, 4H,CβH DOPA & Phe], 1.42 [s, 9H, Boc].

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+Na+H]⁺500.18 (calculated), 500. 02 (observed), [M+K+H]⁻ 516.16 (calculated),516.24 (observed).

3. NH₂-L-DOPA-L-(4F) Phe-COOMe 6:

This compound was synthesized as described for 9a.

¹H NMR (DMSO-d₆, 400 MHz, δ_(ppm)): 8.92 & 8.81 [s, 2H, 2×OH], 8.02 [b,2H, free NH₂], 7.27-7.09 [m, 4H, aromatic proton Phe], 6.67-6.48 [m, 3H,aromatic protons DOPA], 4.58-4.52 [m, 1H, CαH DOPA], 3.90-3.86 [b, 1H,CαH Phe], 3.61 [s, 3H, OMe], 3.08-2.67 [m, 4H, CβH DOPA & Phe]. ¹³C NMR(DMSO-d₆, 100 MHz, δ_(ppm)): 171.4, 168.7, 162.7, 160.4, 158.5, 145.6,145.0, 133.3, 133.2, 131.4, 125.6, 120.6, 117.2, 115.9, 115.5, 115.3,54.1, 53.9, 52.4, 41.0, 36.8, 36.2, 23.6.]. ¹⁹F NMR (DMSO-d₆, 470 MHz,δ_(ppm)): −(116.25-116.29).

MALDI-TOF (matrix:α-cyano-4-hydroxy cinnamic acid (CHCA)): m/z=[M+H]377.15 (calculated), 377.25 (observed), [M+Na]⁺ 399.13 (calculated),399.24 (observed).

Another two exemplary peptide derivatives have been synthesized usingsolid or solution phase synthesis. The purity and identify of thepeptides was determined using HPLC and MS spectrometer.

Substrates

The following substrates were coated with the peptides in the course ofthe research: a silicon wafer, a silicon wafer with a 100 nm titaniumlayer, a 400 mesh Copper-formvar®/carbon grids.

Surface Modification

10×10 mm Ti surfaces were sonicated 5 minutes in ethanol, washed withTDW and dried under nitrogen. The clean surfaces were dipped in apeptide solution (0.5 mg/mL in methanol) and left for overnight at RT.Then, they were rinsed extensively with methanol and dried undernitrogen.

The desired substrate was cut into a 1 cm² square and cleaned bysonication (5 min in acetone and 5 min in isopropanol). Then, thesubstrate was immersed in a peptide solution at a concentration of 0.1mg/ml and incubated over night at room temperature.

Following incubation, the substrate was rinsed by immersion in water,dried and store in a dissector until use.

Contact Angle Measurements

Conatct angle measurements were carried out using a Theta Lite opticaltensiometer (Attension, Finland). Each experimental measurementconsisted of three repeats, and the reported angles were averaged.

AFM Analysis

Freshly cleaved mica surfaces were dipped overnight in different peptidesolution at a concentration of 0.5 mg/mL in methanol. Then, the surfaceswere washed with fresh methanol and dried under N₂. AFM images weretaken in AC mode with Si₃N₂ tip with spring constant 3 N/m in JPKinstrument (NanoWizard 3).

ATR-FTIR

ATR spectra were recorded using FT-IR (Thermo scientific, Model Nicolet6700) with Ge-ATR arrangement (Harrick Scientific's VariGATR). For allthe surfaces spectra were collected with applied force of 350 N, at 4cm⁻¹ resolution with 3000 scans averaged signal and an incident angle of65°.

QCM-D

QCM-D (Q-sense, Biolin Scientific) was used for the study of peptideadhesion onto Ti surface. Measurements were performed in a flow moduleE1 system. Ti sensors with a fundamental resonant frequency of 5 MHzwere also purchased from Q-sense and used as supplied. Prior to eachexperiment Ti sensors were cleaned with Oxygen/Plasma (Atto, DienerElectronic), followed by rinsing with 2% SDS and TDW and finally driedunder N₂. All QCM-D experiments were performed under flow-throughconditions using a digital peristaltic pump (IsmaTec Peristaltic Pump,IDEX) operating in pushing mode. The studied solutions were injected tothe sensor crystal chamber at a rate of 0.1 mL/min. Organic solventcompatible tube and O-ring were used for the flow system. Peptides weredissolved in MeOH to a concentration of 0.5 mg/mL.

The data were fitted with Sauerbrey model. According to this model themass of adhering layer is calculated as

${\Delta\; m} = {- \frac{{C \cdot \Delta}\; f}{n}}$

where C=17.7 ng Hz-1 for 5 MHz quartz crystal and n=1, 3, 5, 7, 9, 11,13 overtone number.

X-ray Photoelectron Spectroscopy (XPS)

The X-ray Photoelectron Spectroscopy (XPS) measurements were performedusing a Kratos AXIS Ultra X-ray photoelectron spectrometer (KratosAnalytical Ltd., Manchester, UK). Spectra were acquired using the Al-Kαmonochromatic X-ray source (1,486.7 eV). Sample take-off angle was 90°(i.e. normal to the analyzer). The vacuum pressure in the analyzingchamber maintained to 2.10⁻⁹ Torr. High-resolution XPS spectra werecollected for F 1s, O 1s, C 1s and Ti 2 peaks with pass energy 20 eV and0.1 eV step size. Data analyses were done using the Kratos Vision datareducing processing software (Kratos Analytical Ltd.) and Casa XPS (CasaSoftware Ltd.).

Evaluation of the Layer Thickness by XPS

Using the XPS measurements, it is possible to calculate the thickness ofthe assembled layers. We have done so using the standard attenuationrelations of the photoelectrons emerging from different sample depths.The thickness calculation is based on the Briggs et al. method andothers. For the Au substrate, the overlay thickness d (nm) expressed as:

$d = {\lambda_{o}\sin\;{{\theta ln}\left( {\frac{N_{s}\lambda_{s}I_{o}}{N_{o}\lambda_{o}I_{s}} + 1} \right)}}$

where I_(s) and I_(o) are the intensities of the peaks from thesubstrate and the overlayer respectively, the substrate is the Ti 2psignal, and layer is the sum of the intensities of C 1s, O 1s, N 1s andF1s peaks, θ is the takeoff angle (in our case sin θ=1) and N_(s) andN_(o) are the volume densities. The inelastic mean free paths (IMFPs)parameters for substrate (λ_(s)) and for the overlayer (λ_(o)) assumedas 2.18 nm and 3.3 nm respectively. Calculated, using S. TougardQUASES-IMFP-TPP2M software (http://www.quases.com). Inelastic electronmean free path calculated from the Tanuma, Powell and Penn algorithm[Penn, 1994].

Ellipsometry

The thickness of the peptide-based coating was measured using α-SEspectroscopic ellipsometer (J. A. Woollam, Lincoln, Nebr., USA).Measurements were performed at wavelengths from 380 to 900 nm, at a 70°angle of incidence. The optical properties of the substrate were fittedusing standard Si with a 50 nm Ti. The thickness of the layers andrefractive indices were fitted according to the Cauchy model. Thecoefficients of the Cauchy equation were initially fixed for organiclayers (A_(n)=1.45, B_(n)=0.01 and C_(n)=0), and an angle offset waspermitted. Then, the parameters were allowed to be fitted to determinemore accurate values.

Protein Adsorption

50 μL of single protein solution of BSA, lysozyme and fibrinogen (150 μMin PBS) were pipetted onto the substrate in a petri dish. The plate wasplaced in a humidified incubator at 37° C. for 2 hours. The substrateswere then rinsed 3 times with PBS (pH=7.43, 10 mM Nacl, 150 mM), andtransferred into eppendorfs containing 1 mL of 2% (w/w) SDS. The sampleswere shaken for 60 minutes and sonicated for 20 minutes at roomtemperature to detach the adsorbed proteins. Protein concentrations inthe SDS solution were determined using the Non-interfering protein assay(Calbiochem, USA) according to the instructions of the manufacturer,using a microplate reader (Synergy 2, BioTek) at 480 nm. Allmeasurements were performed in triplicates and averaged.

To determine if the coated surfaces prevents protein adsorption, each ofthe examined substrates was incubated with a fluorescently-labeledprotein (FITC-BSA) for 1 hour. After incubation, the substrate wasrinsed exhaustively to wash access protein and the fluorescent signalwas recorded using a fluorescent microscope.

Biofilm Growth

Pseudomonas aeruginosa and Eschrichia coli were grown in TSB medium(Fluka) and LB medium (BD Difco) respectively overnight at 37° C. inloosely capped tubes with agitation (120 rpm) to the stationary phase.Then, cultures were diluted to 10⁸ CFU/mL with TSB, and 3 mL of eachculture were transferred to a Petri dish. Substrates were placedhorizontally in the plate and incubated at 37° C. for 9 hours for theformation of biofilm by P. aeruginosa and 96 hours for the formation ofbiofilm by E. coli. Every 4.5 hours the medium was replaced with a freshone to ensure sufficient supply of nutrients.

BL21 E. Coli strain was grown in LB broth to a steady state. Theexamined surfaces were immersed in the bacterial growth culture. After 1hour of incubation the substrates were thoroughly rinsed with sterilePBS buffer (at least 20 ml for 1 cm² surface), in order to get rid ofnon adherent cells, and placed in test tube containing a clean buffer.In order to determine the number of bacteria adsorb onto the substrate,the test tube was placed in an ultrasonic bath for 5 min. The buffer wasthen diluted ×10 and ×100, spread on LB agar plates and incubate overnight at 37° C. The number of cell forming units (CFU)/colonies wascounted.

Crystal Violet Assay

After incubation, the substrates were gently rinsed 3 times withdi-ionized water, and stained with 0.2% crystal violet for 15 minutes.The stained samples were washed with running water and left to dry inair. Eventually the bound dye was eluted with 30% acetic acid.Absorbance values were recorded at 590 nm in a microplate reader(Synergy 2, BioTek). All measurements were performed in triplicates andaveraged.

Results

The molecular structure of the studied peptides 1 to 6 is presentedbelow. We chose to explore two variation of the peptide: one containsonly one fluorine atom on each of the benzene rings and the othercontains five. In addition, we studied peptides with either L or D aminoacids, since L amino acids are more abundant in natural systems and Damino acid resist common proteases and can present an additionalstability. The third amino acid of the peptide is3,4-dihydroxy-L-phenylalanin (DOPA) (FIG. 2).

To coat a substrate (e.g. gold, silicon, titanium, glass or polystyrene)with the peptide, we cleaned a bare substrate (1×1 cm²) by sonication inethanol, washing with water and drying under nitrogen. We incubated thesubstrates for several hours (3-10 hours) in a 0.5 mg/mL peptide inmethanol. We chose this concentration of peptide since it formed asubstantial coating that gave a good signal in various characterizationmethods. After incubation, we thoroughly washed the substrate withmethanol and dried it under nitrogen. Due to the hydrophobic moieties ofthe peptides, water could not be used as a solvent system despite itshigh polarity. We used methanol as the solvent since it dissolved thepeptide completely, and at the same time allowed it to adhere thesubstrate. Since methanol is a toxic solvent, we also examined othersolvents with different polarities. When we used solvents, such asacetone, ethanol and isopropanol, with polarities that resemble thepolarity of methanol, the peptide-based coating self-assembled in asimilar manner to the methanol solvent system (FIGS. 3 and 4). However,in solvents with high polarity, such as di-methyl sulfoxide (DMSO) and1,1,1,3,3,3-hexafluoro-2-propanol (HFP) the peptide dissolved but didnot adhere to the substrate (FIG. 3).

In order to determine if the peptide indeed generated a “Teflon-like”layer on the substrates and increased their hydrophobicity we measuredtheir contact angle. As we assumed, the modified surfaces (i.e. gold,silicon, titanium and stainless steel) exhibited an increase in thecontact angle indicating an increase in the substrate hydrophobicity(FIG. 5). The contact angle of a titanium substrate coated with peptide1 increased from 43.2° to 68.1°. Similarly, peptides 2, 3, 4, 5 and 6followed the same trend (FIG. 6). We also found a correlation betweenthe angle size and the concentration of the peptide solution, as thepeptide concentration increased the contact angle was larger (FIG. 7).

To characterize the morphology of the modified surfaces we performed AFMtopography analysis to mica and Ti surfaces coated with the differentpeptides (FIG. 8). The AFM analysis of the coated mica substratesindicated that the peptides decorated the surface. Spherical-likeaggregates with a height of ˜0.25-0.50 nm (peptide 1), ˜0.20-0.48(peptide 2), ˜0.20-2.30 nm (peptide 3), ˜0.32-0.65 nm (peptide 4),˜1.00-5.00 nm (peptide 5) and ˜1.02-3.65 nm (peptide 6) appeared on thecoated substrate. Due to the roughness of the titanium surface (Rq˜0.866 nm) we could not detect any morphological changes on the surface(FIG. 9).

We also studied if the peptides indeed present on the substrate usingATR-FTIR spectroscopy. An informative IR frequency range is 3500-3200cm⁻¹ as it corresponds to the N—H stretching vibrations and can indicateon the formation of a peptide film on the substrate. For a titaniumsurface modified with peptide 1 the N—H stretching frequency occurred at3330 cm⁻¹. This IR frequency suggests the binding of the peptide to thesubstrate (FIG. 10). Similarly, the N—H stretching band occurred between3305 cm⁻¹ to 3322 cm⁻¹ for surfaces modified with the additional studiedpeptides (FIGS. 11 and 12). Another informative region is characteristicof the C—F stretching band. Peptide 1 showed a peak at 1315 cm⁻¹, 1245cm^(−l) and 1093 cm⁻¹, while the spectra of the other peptides had apeak between 1310-1000 cm⁻¹ (FIGS. 11 and 12).

The IR region between 1800 cm⁻¹ and 1500 cm⁻¹ is related to thestretching band of amide I and can indicate on the secondary structureof the peptides. The ATR-FTIR spectra of a substrate coated with peptide1 appeared at 1685 cm⁻¹ and 1629 cm⁻¹ indicating an anti parallel βsheet secondary structure. For peptide 2, 3 4 and 5 the amide I peakappeared at (1687 cm⁻¹, 1616 cm⁻¹), (1687 cm⁻¹1612 cm⁻¹) (1686 cm⁻¹1619cm⁻¹) and (1679 cm⁻¹, 1605 cm⁻¹) respectively indicating the same typeof peptide secondary structures on the substrates (FIG. 11). The IRspectrum of peptide 6 had a peak at 1620 cm⁻¹ (FIG. 12), however, thehigher peak shifted to 1696 cm⁻¹, and another peak at 1655 cm⁻¹appeared, indicating alpha helical structure. These may imply on lessorganized assembly of peptide 6 on the substrate. This can be supportedby the intensity of peaks, and signal to noise ratio of the spectrum.When compared to the other spectra, the spectrum differs, and some ofthe titanium peaks seem to appear.

Using quartz crystal microbalance with dissipation mode (QCM-D) westudied the real-time adhesion of the peptides to titanium substrates.Each of the peptides dissolved in MeOH were injected into a flow cellcontaining a Ti coated sensor. The injection of peptide 1 resulted inchanges in both frequency (f) and dissipation (D), this indicates on thepeptide binding to the titanium substrates. Upon washing with MeOH, weonly observed small changes in the frequency and dissipation; thisindices the formation of a stable film on the surface (FIG. 13).Peptides 2, 3 and 4 exhibited the same trend, while the shifts resultedfrom the adherence of peptide 5-6 to the sensor were lower. (FIG. 14)These differences suggest that the adhesion process is affected by thepresence of fluorine atoms. The change in frequency is mass dependant,thus the smaller change in the case of peptide 6.

TABLE 1 Quantitative analysis of peptides 1-6, according to theSauerbrey model. Peptide 1 Peptide 2 Peptide 3 Peptide 4 Peptide 5Peptide 6 Thickness  9.11 ± 0.05  7.3 ± 0.3  5.4 ± 0.5  5.6 ± 0.3  3.4 ±0.5  1.7 ± 0.3 (Å) Mass/Area 72.1 ± 0.4 57 ± 3 43 ± 4 45 ± 2 27 ± 3 13 ±2 (ng/cm²) Density 767 ± 4  824 ± 13 760 ± 37 769 ± 30 717 ± 44 805 ± 15(Kg/m³)

It should be noted that the QCM-D experiments lasted 40 minutes andtherefore measured only the beginning of the coating process. UsingX-ray Photoelectron Spectroscopy analysis we were able to characterizesurfaces that underwent a prolonged incubation with the peptide toensure the complete modification of the Ti substrates. In comparison toa bare Ti, the signals resulted from the modified substrates indicatedthe presence of carbon, nitrogen and fluorine. (FIGS. 15 and 16) Thesesignals indicate a deposition of the peptide on the surface. The averagethickness of the peptide layer evaluated by XPS was 3.9±0.1 nm, 4.3±0.1nm, 3.9±0.1 nm, 4.41±0.03 nm, 4.2±0.1 nm and 3.82±0.04 nm for peptides1-6 respectively.

We also determined the thickness of the coating using ellipsometry. Byfitting the measurement to Cauchy film model, which is suitable fororganic coatings, we evaluated a thickness of 3.41±0.05 nm, 3.46±0.04,3.48±0.03 nm, 3.36±0.05 nm, 5.2±0.1 nm and 3.66±0.04 nm for peptides 1-6respectively. These findings are with agreement with the resultsobtained by XPS analysis.

The process of biofouling initiates by the adsorption of bioorganicmolecules, in the form of polysaccharides or proteins, onto a substrate.These bioorganic molecules mediate the subsequent attachment oforganisms, therefore, investigated the resistance of the peptide-basedcoating to protein adsorption. A bare Ti surface and a coated Tisubstrate were incubated in a protein (either Bovine Serum Albumin(BSA), or lysozyme) solution at a concentration of 150 μM for 2 hours at37° C. To determine the adsorbed amounts of the proteins on thesubstrates we used the non-interfering protein Assay™ kit. The adsorbedamounts of BSA and lysozyme on the peptide coated substrates werenegligible and below the detection limit of the kit (FIG. 17).

To assess the bacterial attachment to the surface, bare and peptidecoated substrates were incubated in innocuous of P. aeruginosa and E.coli for 9 and 96 hours respectively. These incubation times allowed theformation a biofilm by the different bacterial strains. Afterincubation, we washed and dried the substrates, and stained them with 2%(w/w) crystal violet. Crystal violet dye is part of the gram staining ofbacteria and stains bacteria in purple. Using an optical microscope weobserved a thick and dense purple layer on the bare titanium surfacewhich indicated a thick bacterial coverage of the substrate, while onthe coated titanium we only detected sparse bacteria (FIG. 18). Toquantify this result, we extracted the crystal violet stain from thebacteria using 30% acetic acid and measured its absorbance. Theabsorbance of the crystal violet is proportional to the number ofbacteria attached to the surface. For surfaces inoculated with P.aeruginos we observed a reduction of 93% in the amount of crystal violeton a coated substrate when compared to a bare substrate (FIG. 18). Forsurfaces inoculated with E. coli, a reduction of 72% in the amount ofcrystal violet was detected (FIG. 18).

Morphological characterization of the coated substrates

The peptide films were prepared by the dip-coating. Unless notedotherwise, all experiments were carried out with a peptide concentrationof 0.01 mg/mL. The films were deposited on either silicon wafers,silicon wafers coated with a 100 nm of titanium layer or 400 meshCopper-Formvar®/carbon grids. Using electron microscopy, the folds anddefects in the film were identified, indicating the formation of a filmon the substrate (FIG. 19).

Proteins Adsorption to the Peptide-Coated Surfaces

In order to determine if the peptide-based coating indeed resistedprotein adsorption, the modified surfaces were incubated with FITC-BSA(a fluorescently-labeled protein). After a thorough washing, thepresence of the adsorb protein to the surface was analyzed usingfluorescence microscopy. Results from this experiment clearly showed astrong fluorescence signal indicating on an extensive protein adsorptionon the bare silicon substrate when compared to the weaker signal fromthe modified surface.

Antifouling Activity of the Peptide-Coated Surfaces

To determine the antifouling activity of the peptides, the modifiedsilicon surfaces were placed in BL21 E. Coli bacterial culture. Thesurfaces were then rinsed, sonicated in a buffer and the buffer wasspread on agar plates and cultivated. The colonies were counted and thenumber of colonies forming units (CFUs) was calculated.

As indicated in Table 1, the number of CFU on the modified surface waslower by two orders of magnitudes when compared to the bare siliconsurface.

TABLE 2 CFU per cm² of Si Bacterial Si coated strain Bare Si with thepeptide E. coli 1.1 × 10⁵ 1.3 × 10³Surface Coverage

In order to establish the ability of the peptide to cover a substrate,peptide 8 was synthesized in such a fusion that an amine group would belocated in a non-adjacent position to DOPA. Then, the peptide wasconjugated to Fluorescein through its amine termini and deposited on atitanium substrate by dip coating. Results indicated the absence offlorescent signal from a bare titanium substrate and a strong signalfrom the modified surface. This indicated that the peptide indeed coatthe substrate.

Perfluorinated Derivatives

A perfluorinated DOPA (herein referred to as “f-DOPA”) demonsartedsubstrate-independence and superhydrophobicity as a coating. The in situsuperhydrophobic, selfcleaning coating composed of the material wasapplied to various substrates, such as gold, glass, polydimethylsiloxane(PDMS), PET, vanadium foil (V foil), zinc foil (Zn foil), and titaniumdioxide (TiO₂). The manipulation of the water flow was also madepossible by this coating approach.

As shown in the schematic below, the perfluoro group was attached ontothe carboxylic acid in L-DOPA to increase the hydrophobicity of theresulting polymer films. Briefly, L-DOPA was coupled with1H,1H,2H,2H-heptadecafluoro-1-decanol via esterification withprotection/deprotection of the hydroxy and amine groups. Prior tosubstrate coating, the oxidation process of f-DOPA in solution wasinvestigated by UV-Vis spectroscopy. The acetonitrile stock solution off-DOPA (4 mg mL⁻¹) was diluted to 0.05 mg mL⁻¹, and 0.5 mL of thediluted solution was used for reliable UV-Vis analysis.

The UV-Vis spectrum of f-DOPA showed a characteristic peak at 283 nm,corresponding to the symmetry forbidden transition (La-Lb) of thecatechol moiety in f-DOPA. The peak intensity at 283 nm decreased uponthe addition of the aqueous sodium periodate (NaIO₄) solution (1.25 mM;0.13 mL). As the reaction progressed, a new peak appeared as a shoulderover the peak at 283 nm and was observed clearly at 330 nm after 2 h.The peak at 330 nm indicated the oxidation of the catechol moiety inf-DOPA to o-quinone. In addition, the formation of dopaminechrome wasevidenced by a weak, broad peak at around 480 nm. The UV-Vis spectra,therefore, confirmed that the reaction conditions employed were suitablefor f-DOPA coating.

Various substrates were coated with polymerized f-DOPA, such as gold,glass, PDMS, PET, V foil, Zn foil, and TiO₂. To the acetonitrilesolution of f-DOPA (4 mgmL⁻¹) containing a substrate an aqueous solutionof NaIO4 (100 mM) at the final ratio of 15:2 (v/v) was added. After 12h, the substrate was washed with acetonitrile, and the coating processwas repeated with a fresh f-DOPA solution. After coating, all thesubstrates became brownish or dark-colored, indicating the formation off-DOPA films, except for the V foil that was black before coating.

X-ray photoelectron spectroscopy (XPS) analysis also confirmed thesuccessful coating of all the substrates tested. For example, thecharacteristic peaks of f-DOPA at 688.0 (F 1s) and 290.7 eV (C 1s) wereobserved after coating on gold, and the surface elemental ratio (C/F)was 1.03, which was nearly consistent with that of f-DOPA (1.12). Inaddition, Au peaks at 83.6 (Au 4f7/2) and 87.3 eV (Au 4f5/2) disappearedafter f-DOPA coating, indicating the formation of thick f-DOPA filmswith a thickness of 10 nm or more.

The intensity of the characteristic XPS peak(s) for glass, PDMS, V foil,Zn foil or TiO₂ also decreased significantly after coating. In additionto the incorporation of fluorine, the f-DOPA films were structurallyheterogeneous (i.e., rough), fulfilling the basic characteristics ofsuperhydrophobic surfaces. The scanning electronmicroscopy (SEM) imagesshowed that the substrate was coated with f-DOPA microparticles, rangingfrom 1.0 to 2.0 mm in diameter, which were hierarchically composed ofsmaller nanoparticles. The root-mean-square roughness was measured to be533.92 nm in the atomic force microscopy (AFM) image.

Without wishing to be bound by theory, it is believed that the coatingof the polymerized f-DOPA involved the same processes as thepolydopamine coating, which was thought to result from the presence ofthe catechol and amine groups although the adhesion strength would belower than that of polydopamine due to the perfluorinated group inf-DOPA.

The static water contact angles before and after coating were alsotested, confirming that all the f-DOPA-coated substrates weresuperhydrophobic. Regardless of different contact angles before coating,the coating made the contact angle of all the substrates to be about1551. Interestingly, PTFE, which exhibits the low surface energy (19.1mJ m⁻²) and is non-sticky, also became a self-cleaning, superhydrophobicsurface with a static water contact angle of 1491 after f-DOPA coating.

The wetting properties were further investigated by the tilting-platemethod that measured the dynamic contact angles, because it wasessential in the confirmation of self-cleaning properties to investigatethe dynamic water contact angles and surface free energies. Theadvancing (y_(adv)) and receding (y_(rec)) water contact angles off-DOPA-coated substrates were measured, and the contact angle hysteresis(i.e., (y_(adv)-y_(rec))) of each substrate was calculated. For example,the gold substrate, after coating, showed a low contact angle hysteresisof 9.91. A water droplet on the substrate easily rolled off at a tiltangle of 5.31, which is clear evidence of self-cleaning properties. Allother f-DOPA-coated substrates also showed the low contact anglehysteresis and self-cleaning properties with low sliding angles of 2.51to 6.71. In addition, the surface free energy (gS) was calculated basedon the Owens-Wendt geometric mean equation that divides the surface freeenergy into the dispersive (gDS) and polar (gPS) ones.

The surface free energy (gS; gS=gDS+gPS) of each surface was determinedby measuring the contact angles with water and diiodomethane (CH₂I₂).The surface free energy of the f-DOPA-coated gold surface was calculatedto be 0.279 mJ m⁻², and the other substrates have the surface freeenergies between 0.2 and 0.9 mJ m⁻². These values are extremely low,probably because of both the structural roughness and the incorporatedperfluoro groups. For comparison, the surface free energy of a smoothsurface modified with CF₃ groups in hexagonal close packing was reportedto be 6.7 mJ m⁻². In this system, the simple f-DOPA coating, therefore,led to structurally heterogeneous rough films of perfluorinatedmaterials without any further treatments, which definitely contributedto reduction of surface free energy and realization of superhydrophobic,selfcleaning properties.

Interestingly, the wetting characteristic of the f-DOPA films waschanged to non-superhydrophobic by simple O₂-plasma treatment: after 1min of treatment, the static water contact angle of the f-DOPA-coatedgold substrate was changed from 154.451 to 124.181. The spatio-selectiveoxidation of the film could be utilized for manipulation of waterdroplets and flow. For example, when a small square area of the film wasmade relatively hydrophilic by plasma treatment, a water droplet wascaptured at that hydrophilic area after fast rolling on superhydrophobicarea with slight tilting. Droplet-based microfluidic channels could befabricated with ease, demonstrated by a hydrophilic line on thesuperhydrophobic surface.

The invention claimed is:
 1. A compound comprising at least one3,4-dihydroxy-L-phenylalanin (DOPA) group and at least one fluorinatedalkyl group, the alkyl group comprising 8, or 9, or 10, or 11, or 12, or13, or 14, or 15, or 16, or 17, or 18, or 19, or 20 fluorine atoms orfluorinated carbon atoms.
 2. The compound according to claim 1, havingthe general formula A-L-F, wherein A is DOPA, L is a covalent bond or alinker moiety linking A and F, and F is the fluorinated alkyl group. 3.The compound according to claim 2, wherein the linker is selected fromsubstituted or unsubstituted carbon chain, optionally comprising two ormore amino acids.
 4. A method for preventing or arresting or minimizingor diminishing one or more of the following: (a) adsorption of organicand/or bio-organic materials to a surface; (b) adsorption of proteinsand/or (poly)saccharides and (poly)lipids to a surface; (c) secretionfrom cells of multi-organism or of micro-organisms onto a surface; and(d) adsorption of cells of multi-organism or micro-organisms to asurface, the method comprising forming a coat of at least one compoundaccording to claim 1 on at least a region of said surface.
 5. A methodfor inhibiting settling, attachment, accumulation and dispersion oforganisms, organism's secretion of an organic and/or bio-organicmaterial on a surface, the method comprising contacting the surface withan effective amount of a formulation comprising a compound according toclaim
 1. 6. A formulation comprising at least one compound according toclaim
 1. 7. A film comprising at least one compound according toclaim
 1. 8. An article or a device comprising at least one surfaceregion coated with a film according to claim
 7. 9. A compound selectedfrom the group consisting of


10. A formulation comprising a compound according to claim 9


11. An anti-biofouling film comprising the compound:


12. The compound according to claim 2, wherein the linker moiety is analkylene comprising between 1 and 40 carbon atoms.
 13. The compoundaccording to claim 12, wherein the alkylene comprises at least oneinner-chain aryl group.
 14. The compound according to claim 2, whereinthe alkylene comprises at least one heteroatom selected from N, O and S.15. The compound according to claim 1, wherein said3,4-dihydroxy-L-phenylalanin (DOPA) group and said at least onefluorinated alkyl group are associated via an ester group, an amidegroup or an amine group.
 16. The compound according to claim 1,comprising one DOPA group and one fluorinated alkyl group having 8, or9, or 10, or 11, or 12, or 13, or 14, or 15, or 16, or 17, or 18, or 19,or 20 fluorine atoms.
 17. The compound according to claim 1, wherein thealkyl group comprises 17 fluorine atoms.